Shag:

Thats a copy of the Tamiya .50 cal parts, the styrene ones are dirt cheap. Its ID # 0225094 - V & W sprues, $10 list from TamiyaUSA, less if you buy 'em thru Karen at the AAF Tank Museum. I've got 3 of 'em, and plan on buying a few more.

BYA may be carrying more parts now, as that .50-cal is made by AFV-Model, and Axel-Modelbau is marketing a few of the AFV-Model parts. I noticed it the other day when I looked for the repro of the Leo 1A4 MG3 assembly, and found it there under AA-16-313 lising, which I noted is AFV's part sequencing.