This has come up a few times. Here is some info from past discussion on the topic.
CGW/Omega Steel Frame Parts comparability. Schmkey
Source Link:
http://www.czfirearms.us/index.php?topic=79658.msg580117#msg580117The Omega system is much like the "classic" lock work, i.e. virtually all parts will interchange. But the 75B/0 metal framed guns do vary slightly from the P-07/09:
1) The slide only in the 75B/O uses the exact same parts as the classic series, i.e. firing pin, FP spring, barrel, sights, recoil spring, etc.
2) 75B/O grip frame uses the exact same hammer spring rates as the classic 75 models
3) Lock work parts in the 75B/O will interchange with the P-07/09 perfectly. The only caveat is the roller, which is different in the 75B/O. Our rollers will not fit the 75B/O.