Click,Click,Click!

Have not been able to make checks that have been posted until today. Had to have cataract surgery and then came down with bursitis in my right shoulder. To day I managed to do a couple of checks. Recleaned battery posts, removed wires at starter relay and cleaned terminals, removed and cleaned terminals at starter solenoid, checked battery voltage (12.75), voltage at starter relay (12.75), step 4,5,&6 (67Dart273) checked out o.k. I am beginning to think that the starter has gone bad. Thoughts on this are please. It is a mini Chrysler starter. Some time back when I removed the headers, I removed the starter and wrote down a number I found on it. The sticker on the starter stated that it was a Chrysler unit with the number 128000 printed on it. Does anyone know if this sounds correct? If not can you recommend a mini starter to use.
Bolts up to a 1965 Dart GT with a Commando 273.
If anyone has other test that I can do, let me know. Thanks for all the help.