generator, regulator or cut out

Trying to figure out my electrics here. I aim to take my generator in for a rebuild. How do I know if I have the stock 'cut out' or a voltage regulator, & is there a difference? Also, regarding the 3rd adjustable brush, is there a best way to set it and leave it? I won't be working the tractor, just getting her back to prime shape and polishing, leaning on 'er, or parading. By the way, this is a 1949 C and as far as I can tell, hasn't had much work done in the past besides basic maintenance. Thanks for your imput!

The third brush with a voltage regulator, will need to be set to the max output. (as close to the fixed brush as possible)
With no way to look at them, the VR and the Cutout look similar.
If there are 4 terminals on the device (L, BAT, GEN,FLD) then it is a vr.
If there are three, it can be either a VR or cutout.
If it are three, and the F terminal is not connected, and the Light switch has 4 positions and a wire connects from the light switch to the F terminal on the gen, and the Bat connects to the Amp meter, and the ARM connects to the GEN A terminal, it is a cutout, with operator control of charging rate. L for daytime operation, H for charging at first, or when the tractor is shutoff and started repeatedly, and D for dim lights and full charge, B for bright"ish" lights and full charging rate.
If it has a 3 position light switch it will more than likely have a VR.
Complex, but that is the story. Jim

Thanks, Jim. That's helpful. After the rebuild, I imagine it's more likely that they (or I) will have to install a VR. I imagine the cut out is obsolete now. Yes or no? What's the difference between the two? Does the cut out just interrupt charge to the battery? Curious.

The Voltage regulator adjusts the generator output to limit the charge rate according to the needs of the battery, and lights/electrical loads. It maintains a 7 to 7.2 volt charge rate and will top off the battery, and not over charge it. It also contains a cutout relay that is the same as a stand alone cutout relay.
A generator in operation has an almost direct link to the battery negative and to ground on its frame.
As long as it generates more volts than the battery it is happy. If the idle is low, or lights are on at low speeds, or the engine is off, the generator would be a direct connection to ground and thus in short order it would overheat and burn up. It would draw as much or more than it can produce. It is thus necessary to disconnect it as soon as its voltage is less than the bat voltage. The cutout does this, preventing excess discharge.
The voltage regulator sees gen output, and varies the F terminal path to ground. From full ground max output, to just keeping up with a light demand, it senses the needed voltage, and grounds the F terminal appropriately. This grounding (on this A type system) is the only way the field is energized, it is fed voltage inside from the third brush, or from the Arm terminal to get its power source. Jim

The C Farmall you have is the device mounted on top of the gen. If it is its a cut-out. If it is mounted on the bottom of the bracket that holds the gen you have a generator unless someone has did some changing around just remember its an old tractor and you dont know when it was built as you didnt mention any serial#s or cast code #s. take it along with the gen when you go to the shop.