Yeah, the $200 tax on a not-so-good suppressor does make it steep. As mill-heavy as this part of ARFCOM is, I figured someone would've built one himself that was a bit quieter than the originals.
I suppose you could do a so-so suppressor on the muzzle, and then do an integral under the handguards. MV would drop and it would be a trick to get it to run. Lower M193 to 5.7x28mm velocities, but a lot quieter than the original.
$400-$600 of tax stamps, however. Might as well do a 1:7" twist bbl & run Agilla SSS through the small can. Or throw .17" HMR or .22" WMR in there.
Wonder if you could squeeze a KelTec .22" WMR mag into a GI 20 or 30 rounder... If you could get it to feed far enough back to get a 16" bbl, and integrally suppress it under the original moderator shape, maybe only $200 in stamps, no?