Original equipment type Delco coils are on Ebay pretty regularly, and ballast resistors as well. Since the PC Patrol zaps Ebay links as soon as they're noticed, it's pointless to refer you to specific auctions.
The black phenolic solenoid cover is the thing that probably needs to be changed to get the "I" terminal back. Inside, it has a contact that touches the copper disc that transmits battery voltage to the starter windings when the solenoid engages, and drops the voltage off again as soon as the start switch is released. It's possible you might be able to swap the cover from your old solenoid and get back into business that way. Just transfer all the connectors to the old cover, and be careful not to break any of the small wires from the cover to the solenoid. The small wire that attaches to the lower terminal is particularly important- - - -it's the downstream end of the "pull-in" winding that makes the drive gear engage, and it's copper-welded to the terminal. Some rebuilt solenoids have that wire soldered to a ring terminal that's held in place by the connector stud. Good luck!
Drop me a private message if you like and maybe we can go into more detail on the design and function of the key start system- - - -it's considerably different than the pedal start setup used on most trucks.
Jerry
