How'd you get Lend/Lease stuff into the States? I believe that silly law applies to accessories too. Not that I'd bet on it. Just curious. Or are you buying 'em? If so, I think the ITAR rules apply. No exporting scopes without the daft Federal permit.
Anyway, there was an M81 with the mount on Jouster's WTS page, in 2009, listed at $4500US and the guy was asked why so cheap.