A Buck "301" with BG-42 blade steel. Ivory Micarta covers. The workmanship is of custom quality as these were made by the Buck Custom shop.
Before the advent of PM steels, BG-42 was the creme de la creme of blade steels. Stainless and has superior edge retention compared to 154CM or its cousins. The alloy was always hard to obtain. If memory serves, Buck said that they would not make any more knives with BG-42 blades.
This was a special run made for the Buck Collectors Club. I'm not a member, but they came up with a couple of extras and I was able to snag one.