I picked up a well used Argentine Sistema 1927(1911A1 Clone)from Lipsey's and have started rebuilding and learning as I muddle through it.

Question 1:
The pistol had a nasty trigger and failed the diconnector safety check so, I ordered up parts from Brownells(Nowlin diconnector + EGW sear) Trigger pull is now great & the disconnector works fine. However, the safety is now more difficult to engage(it passes the Cylinder&slide safety check in the FAQ's-btw). I can push is up with my thumb but, do have to shift my grip now.  

Do I need to stone/sand the contact area with the new sear slightly?

Question 2:
The pistol had the finish buffed off some time in the past and the buffer wore away most of the grip screw bushings. I backed out the old bushings carefully with vice-grips and the threads look clean and unmarred. However, when I began to hand thread in the replacement bushings from Brownell's, they began to bind shortly after engaging the receiver threads.

How hard should these be to thread in?  Can anyone tell me if the Sistema's had a slightly different thread pitch? I've never tried but, should I find a tap to chase the threads?

Thanks for any input!

Yes and yes. But.....#1..Very carefully..do the safety only , they are replaceable. #2 yeah, most likely a different thread altogether. Take a new bushing to the hrdw store and get the correct tap. Good luck.

Short history and shooting review of a sistema.

www.cruffler.com/review-june-00.html

more info

forums.1911forum.com/showthread.php?t=68064

All parts should be interchangeable with colt 1911 parts.