hopefully this will help those who have just found this page or perhaps someone that has posted in the past...
Magazines pro-mag will work .. stated for witness .. but they work in my ta-90
I also got 2 from a fellow in alaska. not promag.. but he said they were made in the US ... I filed just a bit of the top of the mag-release slot and they fit and released just fine.
parts maybe just a bit difficult to find ... still looking into a few sources..
Hennings .. google or bing search .. grips for witness work just fine..
holsters? .. lol.. so far a beretta 92 works.. will let you know if a cz hoster fits when I find one a bit on the less expensive side..