Making a .30 carbine AR wouldn't be hard. Olympic had barrel blanks there in stock and the rifling machines had boxes of blanks at the end of each. You could get a blank done and go ahead with it...even if you just started with a rifled blank and went from there...wouldn't be hard. Did we find it used standard mags? I know we discussed this before...
Matter of fact, here's a thread from outside that shows you some pics. OA2.org View topic - Oly 30 carbine rifle