I just installed a set of replacement screws from Tom Carter on the old "pheasant gun;" the old ones were buggered and one was an improper replacement.
Tom's screws are great! I ordered the "generic" ones (standard threads, no timing) and they fit the 1882 toplever gun without problems. I had tried interchanging with my older Parker "coach gun" screws, and the thread pitch is slightly off. Tom can tune the tightness, and time them, for any need.
Now I just need to figure out how to "patinate" the shiny new screws to match the gun.
Thanks Tom!