Regarding the original rifle in this thread, the fact that Cowan's specifically mentions the gun is void of a British Firing Proof and most likely assembled from leftover parts could indeed answer as to why it isn't in the Parker-Hale books.
Addendum: Speaking of M85 in auctions, any results on 00248F? It just got listed at Rock Island Auction: https://www.rockislandauction.com/de...fle-with-scope . Quite a high estimate.