I know that this is a little off the wall, but does anyone make a after market slab-side lower like the SP-1? ..At this point I just want to have it ready in case we get our way and I can put it on my SP-1 upper when the ban sunsets. I would like to find a used Colt SP-1 lower, but the price is just to high for my taste. (I already have one on my carbine) I already have a preban A-2 style lower on it now, but would like to take this lower and make a different rifle.

Thanks...

Nope. There are no SP1 type lowers made.  In fact, as far as I can tell, there are no lowers currently being made that are anything but semi auto versions of the M16A2 types.  I'd love to find an M16A1 clone that wasn't preban, but nobody makes one of those either[;D]

Have you thouhgt about getting an 80% lower and just milling the outside also to make it "slab sided"?