Further examination showed that the front end of the sear had been worked on to reduce the trigger pull. This drops the rear end of the sear so that it engages with the trigger blade sooner than it should and in this case before it (the trigger) was being blocked by the safety. I am sure that a new sear is the correct fix, but I don't have one yet (I will get one). I bent the rear part of the sear up about .020 so that the trigger blade engaged the safety first and now it works just fine. Thanks again to David Williamson as I can reassemble the lock easily using his fixture for doing that. Now there is no play in the trigger when the safety is on and you can't release the hammer with the safety on. I.E. it now works perfectly. this gun was made as one of the first Specialty grades (1912) and is in beautiful condition. I undertand that it was refinished by Buck Hamlin.