Thanks for the reply Kurt--I've got a line on a one-piece steel tunnel-type see through mount mfg. by CZ back in the '70s that also looks like it will work--any thoughts or opinion on that? It's a $130 and the guy will take it back if it doesn't work. My 21H had Weaver bases attached when I bought it, so it's already got two holes drilled fore and aft--not sure if the pattern on the EAW base would work or not, but I'll look into it. I'll check out the MAK as well.
Best,
Malcolm