Recently picked up this 91 date stamp pre-B. I know scrolling through previous posts that there were a few options for magazines:

1. Go and buy the SP-01 10 rounders or the 18s. I know Greg Cote is recommended but the 18s are OOS and everywhere you go they are 50+ after tax and ship.

2. Find someone with original pre-b 15s or 16s and pay out the nose.

3. Do some filing and open the magwell. 

I went for the third option, but had some issues. I removed a bit of material and was able to get my SP-01 19 rounders to catch on the magazine release, but the width of the mags became the problem and would bind up the trigger bar. Is it just the geometry on the 19 rounders that makes them wider, and as such a regular 75B mag should work now? I am sure someone has some to compare, but unfortunately all I have are compact mags and the big 19 rounders. I had no concern filing the frame, but thinning the metal on the trigger bar seems more dangerous.

  
Second question is on holsters. I know the frame on the pre-b and b is pretty similar, so most holsters should work, but the trigger guard being a round vs flat changes the geometry that might effect holsters. Kydex often locks on the guard, so maybe leather is better and certainly more aesthetically pleasing. I am just looking for something to wear around at the range or outside so a comfy OWB would be best. If anyone has suggestions I am open.  

'91 Pre-B Mags and Holster questions