Need help identifying and with brakes

Hello, I am a 19 year old and Im currently working on my grand fathers Massey Harris. The cool thing about this tractor is it has been in the family since my grandfathers father(potentially uncle) bought it new during the 40s, I think. Memories can smudge over the years so Im just taking it as its been in the family since about the 40s. I would love to know its actual year.

The only numbers for identification I could make out was
Model No. 30-GR and "1120" on the bottom part of the plate, I don't know what that number specifically means.

It's gas. At some point it was converted to 12volts ignition.

The problem is I need to fix the brakes. When depressed, they do nothing. I pulled off the left side(if looking forward on tractor) housing and pulled out the old shoes, they look asbestos. They are also heavily degraded. I have yet to pull off the right side, but I imagine it would be in similar shape. I can't find mention of a 30-GR with the 1120, so I cant find shoes(or rather, linings).

Also, is there a way to know if the drum is still good? It cannot be removed without a lot of work and if it is still in spec I wouldnt try to remove them.

Thanks for the help you guys can provide, Im gonna be returnining to this forum for more in the future. This tractors gonna be a good yard machine.

Hello interesting tractor, G stands for Gas engine and R stands for row crop. The Tractor is a Massey Harris 30 and the serial number 1120 makes it a 1946. If the brakes have a part number you might be able to cross the at a NAPA store you would be surprised at how meany parts the have for these old tractors. I am 18 and just getting in to the hobby to I already have my second tractor that I am working on It is my great grand fathers Farmall H witch he bought in the 1970's.

Early tractors used expanding band brakes, late models used shoe brakes, on pair each side. Band brakes may need to go somewhere to be relined. Make sure there's no oil leaking on the brakes either, drums may need pulled to replace the leaking seals behind them.

Fortunately there was no leakage on one side. To my understanding if I get the linings I can rivet new ones on(the old asbestos is just riveted on)

Does anyone know where to find the brakes? Either a full assembly or the linings and rivets.