...the RMK model #18 was conceived of in early '63, and was first shown in a catalog insert with the fall '63 catalog.
The first knives were made with O1 carbon steel RMK model #14 Solingen blades.
Gaddis' page 202 shows a picture of a fulltang (to the cap) riveted splitback crutch tip Solingen blade model #18 taken in Jan. '95.
Gaddis' page 221 shows a late '65 Orlando stamped splitback #18 with a comment that the tang ended 1.5" from the 'mouth' of the handle, i.e., the opening...ergo, a 3.5" tang.
Gaddis' page 231 states that by late '74 the crutch tip was done away with. So, now we've narrowed them down to 9-10 years...so far so good.
Moving on to the Intersquare CD...
Crud, the PC is on the fritz again and won't load the CD...
I'll come back and try to finish this later, or someone else will do it for me...
I'd wager late '60's on the Splitback, early '70's on the smooth snap.
Hope that helps Rich
"For trade, one outdated dysfuctional PC, trades for Crutch tip RMK model 18's only..."
*out