Can you post some more pics? Looks to be Frankenstein a little. Its gear drive. Some engine numbers would help too. Frame notch doesn't look OE like 147 would

Could be a number of issues. The starter/Generator, regulator, wiring, or loose connections, or multiple issues. Have you charged the battery? Being it was a pulling tractor it only had to have juice for a few minutes at a time so they could have just jumped it off and used a good hot battery. Charge your battery and then jump it off, it should run as long as the battery last. There is a section that has the diagrams and technical info. Good luck.

Welcome to OCC! Congrats on your 126!

Hey Bud, welcome to OCC. Glad to have ya. According to my research, it is a 1971 model 126. Good luck.

Yes dropped new battery fired right up after 2 years of sitting.. Only would run with it completely choked and low RPM couldn't idle it up without it dying... Checking into the carb... But the battery eventually died so I'm gonna say it's a VR problem... Gonna hook the ground back up and see what other problems I run into! Thanks for the help guys! Will keep posted on this thread as I make progress on it

Good to hear and Welcome to OCC!