Hey guys.  I bought an OC-4 last spring, and I'm just now getting around to tearing into it.  Boy, have I had some surprises!  The guy I bought it from told me 'everything is good - just has some busted studs on the left drive sprocket'.  Couldn't be more wrong!  What I've found so far is basically every bearing from the outer final drive housings is completely trashed - one of the races came out in BB-sized chunks.  The pinion gear is almost unrecognizable, and the reverse idler shaft in the transmission is pitted and galled.

Anyway, I'm not complaining - the guy who sold me the machine didn't know, and it's a good opportunity to get my hands dirty.

What I need help with is the ID plate that has the serial number has been missing for many years, as evidenced by the 2 or 3 coats of mismatched yellow paint where the plate had once been.  Is there anywhere else on the machine I can look?  Can the engine serial number tell me anything?  It's a 3-cyl Hercules diesel.

I don't even know what year the machine is - the front grille does not look like any other OC-4 I've seen in pictures.