should fit the rules
While I don't have them in front of me (ok, so I'm too lazy to open a second browser window!)
I believe a Beretta in that configuration is completely legal for stock/production class. The trigger job you mentioned is mainly just a sear polishing, and maybe a new trigger piece, and the rules specifically allow for mild trigger jobs, different sights and grips that would be on a carry gun, and springs can be changed within reason.
Now, I could be wrong, I haven't read the rules in about a year, so there could be huge changes I am not aware of. (ie is Production class new? or just how you refer to Stock Class?) In which case my Beretta 96FS with Landon level one trigger job, 96D springs, and adjustable Millet sights is NOT in the right class!! Not to mention all those Elite models out there...although they may be restricted to Modified Class now that I think about it...