We have some contacts at Saab-Bofors, so I bet they might be able to locate a bunch of used AT4s. If they are not DDs, then I would think they should be easily importable. If they are easy enough to import, then it would not be hard to create a 12 gauge insert and bring this to market as a transferable firearm with an 07/FFL.
It is interesting if the DD permit is "shall issue." That might make it worthwhile to upgrade to an 09/FFL. We have a half dozen legal projects in process already. Now this comes up! It looks like we'll have to do a bit more research!!!
Compliments to Ajax for bringing this up!