CLOGWYN Hexagons is where the CLOG story begins. Hexagons are mentioned in a newspaper clipping dated to 1967, mentioning Denny Moorehouse and Shirley Smith purchased an old Cinema which served as their workshop for creating climbing gear.
For the CLOG Hexagons there are three generations identified by the manufacturers marks. The manufacturer item dates are not fully locked in, but are listed for reference.
CLOG - 1st generation mfg mark
​- No oval (1966 - 1969)
CLOG - 2nd generation mfg mark
​- CLOG in oval , number outside of oval (1969-1971)
CLOG - 3rd generation mfg mark
​- CLOG and number in oval (1972 - 1975)
The first slung Hexagons came in 6 sizes and had a "CLOG" and "Number" mark on each progressive size.

CLOG - Hexagon - Slung
- #1 - 6
​- C.1966 (First generation being just "CLOG" mark and "Number" mark, no Oval)
- #1 and #2 have straight ends.
The second generation "CLOG" mark inside oval and "Number" outside the oval came in the later 1960s. 
The third generation mark of "CLOG and Number" being inside the oval came in 1972. This third generation mark can be seen on the CLOG products in the Ellis Brigham 1975 catalog.

​Ellis Brigham 1975 catalog showing third generation mark
CLOG - Hexagons - slung (1st generation)
- #1 - 6
- The #4 slung is a solid chock, but then sometime after 1972 the #4 became available having a drilled lightening hole. The #4 with lightening hole in the photo below has a 3rd generation mark. Hexagon #5 and 6 also have a drilled lightening hole. And later around late 1971 (?) a #7 Hexagon was introduced which also has a lightening hole. In Stephane's museum he has a #6 and #7 Hexagon which have very large lightening holes.
Showing the differences between the #4 Hexagons.
Showing the differences between the #6 Hexagons and the #7 Hexagons. Notice the lightening hole sizes. Stephane Pennequin photo.
The first mention that I can find that the #6 Hexagon is named the "Jumbo" and the #7 Hexagon is named the "Mammoth" is in the 1971 Bryan Stokes catalog. (In this catalog photo you can see that item "B9" which is #4, is solid without a lightening hole).
​Bryan G. Stokes 1971 catalog
However, in the 1972 CLOG catalog the #7 Hexagon is mentioned but no mention of the names "Jumbo" and "Mammoth." The number 7 Hexagon is not included in the catalog Hexagons photo.
CLOG 1972 catalog
In the Chouinard 1969 catalog it does first list a #7 Hexagon, but then in the Chouinard 1970 and 1971 catalogs the #7 Hexagon listing was removed. In the Holubar 1970 catalog it first lists a #7 Hexagon, but then in the Holubar 1971 catalog the #7 listing is removed. Not sure why this was happening, but possibly because the #7 was still in development and was not truly available yet? 
Chouinard 1969 catalog
Chouinard 1970 catalog
Holubar 1970 catalog
Holubar 1971 catalog
The #7 Hexagon chocks did become which are shown in the 1971 Bryan G. Stokes catalog and the 1975 Ellis Brigham catalog. Both of these catalogs are located near where the CLOG chocks were being manufactured. Notice #6 and #7 in the catalog photos have the smaller lightening holes.
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Bryan G. Stokes 1971 catalog
Ellis Brigham 1975 catalog
The larger Lightening holes that are shown in Stephane Pennequin's #6 and #7 Hexagon chocks were possibly made sometime between 1972 and 1975. Those two chocks may also be prototypes.
Showing three #7 CLOG Hexagons 2nd generation, 3rd generation and 3rd generation. Notice the differences on how the holes are drilled on the 2nd to 3rd generations. The second Generation holes are sharp and beveled with a extra notch that faces each other. The 3rd generation holes are polished smooth. Notice the length difference between the two 3rd generation Hexagons.
CLOG Hexagons slung. Photo in order by generations, by Stephane Pennequin
I have found a #2 Hexagon that has angled ends. However, throughout the history of the small Hexagons, the Hexagon #1 and #2 had straight ends, so I believe this was angled not by the factory, but somebody modified it at their home.
The CLOG 1976 catalog does not offer any slung Hexagons. The new CLOG Cogs chocks have replaced the Hexagons.
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CLOG Wired Hexagons
Looking at the Chouinard 1968 and 1969 catalogs, a Tiny Brass Hex wired is mentioned. I am not sure if this Tiny Brass Hex was first made in 1966, but Chouinard did not list this Tiny Brass Hex having a number. So I believe the first Tiny Brass Hexagon wired had no number mark on the nut. 
Chouinard 1968 catalog
Chouinard 1969 catalog
In Stephane's photo there are two tiny Brass Hexagons without the number mark, the Brass Hexagons have plastic wire keepers but no plastic on the carabiner loop. 
Stephane Pennequin photos
The Chouinard 1968 and 1969 catalogs lists that the #1, 2, 3, 4 Hexagons are available wired. It is interesting in Stephane's photo the wired Hexagons have no plastic wire keepers and no plastic on the carabiner loop, and the #5 and #6 Hexagon are also wired. Chouinard only listed the Hexagons #1, 2, 3, and 4 being wired in 1968 and 1969.
Stephane Pennequin photo
The Ski Hut 1969/1970 catalog shows wired Hexagons without plastic wire keepers. The Ski Hut 1972/1973 catalog shows wired Hexagons with a red plastic wire keeper and clear plastic carabiner loop.
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Ski Hut 1969/1970 catalog
Ski Hut 1972/1973 catalog
In the Chouinard 1970 catalog the wired Hexagons are numbered #0, 1, 2, 3, and 4. Possibly at this 1970 time the "O" mark was added to the Tiny Brass Hex. Red plastic wire keeper. The wired Hexagons in the Chouinard 1970 catalog are listed as "Clogwyn Wired Nuts," But in the Chouinard 1971 catalog the wired Hexagons are listed as "Clogwyn Wiresling Nuts."
Chouinard 1970 catalog
Chouinard 1971 catalog
In the later 1960s or in 1970 the second generation of wired Hexagons appeared, having a yellow plastic wire keeper, and a red plastic carabiner loop. Then in 1972 a third generation of wired Hexagons appeared having a red plastic wire keeper, and clear plastic carabiner loop.
Showing the different generations of CLOG wired Hexagons
Stephane Pennequin photo
In the CLOG magazine, which I believe is dated late 1972,  a New Brass hexagon is mentioned as brass mini-nut on wire. In this wordage is also a mention of the word "Wiresling" and also a mention of the #7 slung Hexagon being named the "Mammoth."

The original #0 Tiny Brass Nut remained but a newer slightly larger Mini Brass Nut was created. However both of the different size brass hexagons were both marked as #0. 
In the 1972 CLOG catalog it lists the #1, 2, 3, 4 Hexagons wired, which look like the plastic wire keeper is yellow and the plastic carabiner loop end is red.

The #0 Hexagon (Brass) is listed with the CLOG Wedges, but there is no mention of the second size Brass Hexagon. 
CLOG 1972 catalog
Larger size #0 Brass hexagon
Stephane Pennequin photos
CLOG - Price List September 1974.

Hexagon slung #1 - 7
- It mentions lightening holes in #4, 5, 6, 7

Hexagon Brass A and B
Hexagon wired #1 - 6
The 1975 Ellis Brigham catalog shows the two different sizes of CLOG Brass hexagons, #0A and 0B. The catalog shows the Hexagons all sizes up to #6 being wired. The catalog shows the wire keepers are yellow and the plastic carabiner loops are red. The catalog has no mention of a #7 Hexagon size. 

The color combination of plastic keepers and plastic carabiner loops refer to a second generation of Hexagons being shown in the photo, but Hexagons overall were discontinued in 1976, so when did the third generation of wired Hexagons appear? 
Ellis Brigham 1975 catalog
In the CLOG 1976 catalog only the two small Brass hexagons are listed, #730A and 730B. The Hexagons were discontinued since the newer #1 - 10 CLOG Cogs replaced them.