>>Mac did some work for me sometime back on a little Colt .380 which I have since sold, (I sure wish I hadn't).
There is a great article about Mac in the September/October 2010 edition of AMERICAN HANDGUNNER.
I'm told that since my business partner, Doug McDougall, died in 2004, there seems to be a bit of a "cult" following of our Scott, McDougall & Associates custom pistols. If the email inquiries I get concerning our old builds are any indication, that just might be so. Leaving both you and I wishing we'd hung onto a bunch of SM&A guns.
As for that AH article, I thought it was read only by Roy Huntington and Massad Ayoob. Strange how something you did over forty years ago can still come back to bite you.
Attempting to keep this thread on an NFA level, can you tell us what you're trying to get out of the suppressed MAC-10? Or PM or email me (firstname.lastname@example.org) if you're more comfortable with that.