Two Flints,
1. With my Spencer there was included an Owner's Manual. In it there is an illustrated parts breakdown (exploded view) with part numbers. The exploded view is correct in most, but not all cases, for the 56-50 version, but was OK for what I wanted.
2. I was in contact with both Tammy & Sue at different times. The phone number is 540/722-2017 or you can get their E-Mail address off of the Taylor's web site.
3. I purchased 1 each of the following: Main Spring, Rear Sight Base Spring, Rear Sight Slide Screw, Firing Pin, Stirrup, Sear and Rear Sight Ladder. The total cost, including shipping, was $56.75 in September of last year. I based my list on things that I have seen fail on Sharps actions in the past as well as some other parts that I felt I wanted. The lock work on these is basically a Sharps lock and I understand that Sharps actually made some original locks for Spencer.