Finally got around to working on my "Senior" today - so easy to work on.
Polished every contacting surface, PTFE washers at both ends of the spring, a smear of moly here and there, new leaf spring for the trigger and a new (synthetic) breech seal.
It might not be true to the original in some areas, but the trigger is sooooo much better and it punches Superdomes through both sides of a bean can.
Now that's more like it!