Hi Rick,
Very attractive piece, as expected!
Everything else, apart from the missing parts, seems to be all complete and original, preserved in very good condition. The scrollwork engraving on the dogs also is characteristic of Italy, ca. 1590.
And you are absolutely right about the fact that these complicated wheellock mechanisms sure needed a lot of permanent attention and maintenance. Looks like your lock mechanism got damaged during use in its early years and taken out of the musket for repair which it actually never saw. The point about these Italian locks are that they usually had very strong springs, with the weakest parts being the chain and sear. Yours, too, should have strong springs.
I do think it will add to the value when it is correctly repaired. Just patinate the replaced minor parts to optically match.
Congratulations again,
Michael