The smooth delrin models were a factory experiment a sold to BCCI members thru a special sale in 2011.
I will paste below some of the information on them written by Joe Houser. Send me your email and I will forward the entire sale document. You should have it for documentation anyways. Only these 3, there was not a 302 or 303. Stumps offered a good deal on those and thought about buying them myself but decided not to be greedy since I already had a set.
You made me go look.... my 305 box says CADET also, clearly a typo.
The 300 series are sample/test knives. The shop was exploring the possibility of adding smooth black delrin to our current line of Comfortcraft pocket knives. They ordered enough handles for a test run of these 3 models through the shop. The knives turned out great but marketing decided against this line extension. Each one of these knives comes in a box labeled with the model number, blk delrin, 09-22-11, and the words Made in. Although they forgot to add U.S.A. to the label, the knives were in fact made in Buck’s Idaho plant.
301 Stockman Comfortcraft, smooth black delrin sides, blue Buck medallion, 2011 date code mark. 74 made, limit 4 per club member. $25
305 Lancer Comfortcraft, smooth black delrin sides, blue Buck medallion, 2011 date code mark. 62 made, limit 3 per club member. $20
309 Companion Comfortcraft, smooth black delrin sides, blue Buck medallion, 2011 date code mark. 51 made, limit 2 per club member. $22