Diesel Fifty 9G 1270 W

Can anyone help with a mystery?

I recent brought home an old Cat. Bought it from a widow who didn't know any history on the machine. The grill is stamped DIESEL FIFTY.

The engine ID badge is 9G 1270 W. Looks to be the original four cylinder diesel with gas pony.

Looked all over but can't find the serial number on the frame. I think it should be a "1E-" number, but can't see it.

My questions to the experts out there:

1. Where should I look for the frame serial number? I've searched all over the left rear, and can't locate it.

2. Does the number 9G 1270 mean anything to anyone? Would that be correct for a diesel fifty?

Many thanks,
Sam

9G is a RD7, and at some point an early D7
The chassis tag would be left rear transmission case, but if it had a PCU or a towing winch they were often removed.

Hey gggSam,

Book shows your 9G to be a 1936 model RD-7. Seems someone put a Fifty radiator on it. I've seen others do that when radiators went bad. I had a Gas Fifty with a Rd-7 radiator once. Find your serial on the frame and see if you have matching numbers.