I will try again, thought I answered all of them to the best of my ability with what I know. Keep in mind, the "new guy" under my name isn't because I just joined. I'm happy to now have a functional knowledge of what I have, I have no clue what other possibilities exist that everyone is sorting through to provide help. If I don't provide what you're looking for, its because this is my first time through this so if you need additional information please let me know.
1. I have a 53 motor with the correct starter. The old solenoid does not have any markings on it but it doesn't matter because it doesn't work. The new solenoid is labeled 6v and does not have an R terminal. The solenoid does mount to the top of the starter. It has been converted to 12v. I put in a new 12v battery and it has a generator. Beyond the ignition system no other components of the electrical system are currently hooked up.
2. The ignition switch is a keyed ignition on the dash, the foot starter has been removed. Not sure what you are asking with the "spring loaded one or just an on-off ignition switch with separate push button somewhere" The ignition switch has a positive wire from the battery, one back to the S terminal on the starter, and one that goes through a ballast resistor then on the the + on the coil.
3. The coil that came on the truck has no markings on it at all and I do not know if it was changed when converted to 12v. Sorry I don't have any further information, I thought it was possible to tell the difference between a 6v and 12v coil with the ohm readings. It does not indicate internal or external resistor.
4. No part number on the coil. The ballast resistor is porcelain, rectangular with a extension on the top for the bolt. It has a screw connector on each end.
5. Sort of answered in my last post. Ran great then ran rough and stalled. Once when driving (able to start again and limp back home) second time after idling and wouldn't restart. Hasn't been running since then because I have been digging into it. I'm not sure if I have a bypass system either, if you have a resource to help me determine that I can let you know.
Hope this helps you help me and gets you paste the "wild-donkey guess" stage. Thanks again for all the assistance, I appreciate it.