Additional information recovered from gbroker:
Still offers no insight into the odd manufacturer stamp, tho.
Begin quote, source unknown (no citation in the listing)
Experiments had been made with plastic grip materials beginning in late 1941, and by April 1942 it had been determined that the grip material would be "a material similar to Durez No. 1905 with Rogers Board insert" (from United States Army Edged Weapons Report 1917-1945). Durez is a brand name of Phenol-Formaldehyde resin similar to Bakelite. Shortly afterward (June 29, 1942) this specification was written to include other similar thermoplastic resins as Plastic Bayonet Grips, Grade B of SXS-103 Phenolic-Molded Shapes for Small Arms Components. This material is often generically called Bakelite, although that is a brand name rather than a chemical name. The color chosen was black as it was the least expensive and easiest to maintain color consistency.
These grips were adopted prior to actual deliveries beginning on the M1905 bayonets in 1942 and were specified for use on these bayonets. Although it is not impossible that walnut grips were used on very early production of the M1905, it must be considered unlikely that any significant quanitity were delivered with wood grips.
As this resin was expected to at times be in short supply, tests continued to be conducted of other plastic materials at Springfield Armory. Cellulose Acetate Butyrate (commonly called CAB) was allowed as an alternative material. The normal color for this material was a reddish brown. Production of this product seems to have been entirely by Columbus Plastics Products of Columbus, Ohio and most of their production was used by American Fork and Hoe.
After some time in field use, it was reported that CAB was not resistant to the solvents used to degrease the bayonets in the field and would soften and partially dissolve the grips. About 100,000 CAB grips were manufactured before they were discontinued due to this problem in April 1943. From available evidence, it appears that most of these grips were used by AFH, with possibly some small amounts going to other makers. According to the edged weapons report quoted above, "Except for the disruption of production that would ensue for about one month while American Fork and Hoe Company was arranging for procurement of the other type of plastic, there was no reason for the continuing of cellulose acetate grips."
Use of the CAB grips by AFH ended at about the time that production of the M1905 bayonet ceased and M1 bayonet production began. Due to the lack of solvent resistance, many brown grips were replaced by black Bakelite when the M1905 bayonets were shortened, but in limited cases the brown grips were used on the shortened bayonets, including on makers other than AFH.
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End quote from gubroker listing, no citation.
