Thanks d2gary and old magnet

I'll check both around the rivet holes and the oil pan flange later this week when I'm back over where the dozer is stored.

I have used paint remover and a wire scrub in those areas where the tag is missing--even on tags to read them better

serial number is important to get the correct manuals and parts as cat had a constant improvement program.
major part may be the same but minor parts changed and may not be interchangeable.
the clucthes and engine filters changed over the yrs.
plus the many options you could spec a crawler with are just as bad as a car.

Thanks Old Magnet. The serial number was stamped into the sump flange, right where you said to look. 

It also looks like the old girl is leaking a little bit of oil  down there..   

 

That would make her a "48"

if they dont weep a little there is probably no oil in in it. the sealing on these old bit of equipment wasnt all that flash. but you can make them leak free using modern gasket dressings on the cut gaskets aviation no.3 form a gasket works well at filling little imperfections that cuase weeping gaskets. the other is loctite master gasket 515. of course there is the old bush trick of a light smear of grease which works supprisingly well & also allows removal often with out breaking the gasket.

Thats why I didnt understand Squatch's D2 rebuild with nothing on the gaskets, heck I have some gaskets that sometimes leak with the best sealant on them let alone nothing! And no primer or paint on parts, one humid day and it will be a rust bucket. BUT! each to there own.

I'm not really too concerned about a couple of oil leaks. It goes with the territory of operating old equipment. If I have to pull anything off I will make sure to seal it up as best I can. Until then I'll make sure to check the fluids each time she goes to work.

The main thing I need to do now is adjust the tracks, the left hand side is a bit too tight and the right is a bit sloppy.. But boy those 2-3/4in adjustment nuts are pretty damn tight. I'll probably have to give them some heat to get them to move.
Once I have that sorted it'll be time to go push some dirt and see what the old girl can do..
Can't wait for that 🙂

What is the area behind the clutch lever? That looks like the tag.