I don't have parts drawings, but do have the Jack First catalog which has the 1903 & 63 parts lists. They show the same part numbers for the 03 and 63 sear and sear pin. I have a 1903, and the trigger/sear pin is significantly smaller than the hammer pin. Hammer pin measures 0.160". I can't remove the trigger/sear pin to measure, but it is on the order of 0.130".
It is possible that either someone has drilled out the frame or that you have a 1903 sear. It would be interesting if a 63 owner could measure his.
