What manuals should I get?

Looking for advise on which manuals to get for my D2.

I have the Servicemans Referance Book Form 30525,
for the Caterpillar diesel engine (3 3/4" bore 4" cylinder), and the parts book form 6700, for the Caterpillar D2 tractor.

What else should I get, and what else is available?

I've checked out the Cat Legends sight and I'm a little confused at what to get as there appears to be about 30 different OM's for the D2's and several just for the 3J's (I'm assuming OM means Operators Manual).

I purchased Legendary when I first got my D4. They are OK reproductions. I would keep my eyes out for the parts book and operations manuals at the least on venues like EBAY. I am extremely pleased with the investments I made on those.

Good Luck.

bernie