OK, I've done my best to research this all over the web and at the ATF's site and still don't know the answer;  Is it legal to put HK91 fixed stocks on an SR9?  As far as I can tell, it wouldn't cause a conflict with the Clinton Human Rights Tragedy of 1994, but I can't figure out if it would run afoul of the Bush Human Rights Tragedy of 1989.  All I could find on the internet was some guy speculating that a collapsible stock would be a no-no (which makes sense).  Please edumacate me.

SR9s are postban, therefore you cannot put a pistol grip and conventional stock on instead of the factory butthole stock.

Unless, of course, you bring the US parts count up, that is.  Exact number of parts needed, I can't recall, but somebody here knows.  

By "postban" you mean post-1989 import ban, right?  I bought mine in 1990 or 1991 (I don't remember off the top of my pointy little head).

are you a cone head?

[size=1]Shhhh.  Don't tell anyone.[/size=1]

Replace 6 parts with US parts and you can legally have a pistol grip and regular stock.

Most common US parts are cocking handle, hammer, sear, pistol grip, and magazine parts either baseplate and follower or complete US mags made by Thermold which count as three parts.

Many many thanks, [b]Jayson_at_IGF[/b]!  That's exactly the info I was looking for.