So I picked up a Zastava PAP M85 last year and filed my Form-1 in early October. My questions is, what prep work can I do to my M85 short of actually mounting a stock? Can I drill and tap the rear trunion? Can I mount the folding mechanism sans stock? I have SBRd a few AR15s and I know it's bad juju to even have a short barreled upper on the premisses if you don't have a pistol lower, or another SBR. Do I have any options, or do I just need to quit fondling my PAP and staring at the calendar?