Cat pipe layer at auction

I have seen this Cat 62A252  pipe layer listed before. What machine would it have been based on?   6 cylinder engine and street tracks.  It looks all pretty and painted up, but that never tells much.     Check out  "Barnoneauction.com" It is near Sacramento Calif.  Online auction this Saturday.  Just curious.   Grant.

Looks like a D6B to my untrained eye

Definitely based on the D6B. The fiberglass parts are the sure tell. The dash is damaged and the shifter "boot" is missing.
Craig 

For some reason this was on the auction last month but did not sell. I would think that an engine in a pipe layer would not be worked hard or have many hours on it. It might make a good parts machine for someone with the D6B. If it was a D4, I would be drooling over it, but I decided that if I cant drag it home behind my 1 ton pickup, it is too big for me. Darn.