Here's a couple you do not see often. KMK678GCL made for Lipseys. 504 made. NIB
MK512CA. First Mark II Bull Barrel Ruger Drilled and Tapped. Made for Camfor distributors. Can't remember exact number made. Need to check my notes. But I believe about 200 made.
Very very hard to find KMK512GC made for Big Rock Sports.