Big mo electrical question

Hi i posted not long ago i took ownership of a big mo 500, if anyone can shed some light on the electrical outfit on here id appreciate it.
Its set up for negstive ground and the coil is a 12v coil, the regulator seems to be missing but theres a 3 spring unit the power seems to run through (can someone enlightn me on this thing? Ill post a picture) and because theres no regulator i dont know how to polarize the genny to see if it works?
Theres also a resistor (i think, ill add a pic aswell) on the start button...whats the purpose of this?

If the genny is bad and i decide to rewire and pick up a 12v self regulated alternator will the stsrter be suitable? Ive read its a 12v starter and it had a 12v battery on it but i thought i would double check with the experts lol.

Also ill add the serial number if someone could let me know the year of manufacturing?

Any info about this unit would be helpful this is my first tractor so im figuring it out as i go thanks in advance everyone.

Serial

Well it doesnt look like my pictures uploaded maybe i need help with that first lol

One more tryyy...if it doesnt work you can email me and i will send the pictures there sorry [email protected]

No problem with the starter if it is a 6V or 12V. The wiring in the 6V is heaver than the 12V I have been running 6V starters on 12Volts For over 30 years. But yours is 12V if original. To check the gen to see if it charges, take off the two wires from the posts on the gen. Take two screwdrivers scratch a shinny spot on the gen case and on the nuts on the posts. Take one screwdriver and jump the post marked with an F to the case. Then take the other and scratch A to the case. If you get sparks the gen is charging. As far as the 3 unit springy thing I have no idea what that is with out pictures.
MMDEL

Big Mo 500 were built from about 1960 to 66. They are basically an industrial version of 4Star Jet Star series.

"3 spring unit the power runs through" sounds like the regulator with cover missing. Do 2 wires from this device go to the generator?

If you want originality then troubleshoot and fix up the generator system.

If you want least expensive and most reliable system I would convert to a 3 wire Delco alternator. I ask for one for a 1983 Chevy suburban small engine. (should be in $40 range, exchange) On the 2 pin edge plug loop #2 down to output post. Connect #1 to switched side of ignition switch (wire going to coil)or where this wire connects to the coil. Add a 3amp@50 volt diode in this line with marked band of diode toward alternator. Without the diode the engine may continue to run when switch is turned off.

Original starter was 12 volt and does not care if positive or negative ground.

With negative ground check that ammeter goes negative with switch and/or lights on, engine not running. If it goes positive reverse amp meter connections.

Negative post on the coil should go to distributor.

What is the resistance across the + and - posts on the coil? Closer to 1 1/2 or 3 ohms