Don't know history on pump. Been sitting inside. Make offer

Would that be off of a D337 engine like used in a DW 15, DW 20 or 21?? Bill

I really dunno. I assume if you cross match the casting numbers you could find out. I have no way of finding out

Can anybody make out the casting number and I'll try to look it up?

looks like 5M7865?

Hi Team,
also has a D343 engine look about it as they also used the flat back mounting, this pump has the same D343 looking turbo return elbow. I cannot recall where the D337F turbo return went.
Elbow part no I have from a D343 engine in a 630 Tractor book is 2M6643.
I think on the D337F the turbo return was in different location.

From the pix provided, Bill has made a good call as both pumps are very similar--in fact I call the D337F the Father of the D343 as there are many similarities/carryovers. Some of these started in the Early Series D337, the trend to rear timing gear drives, angled exhaust manifold faces and so on.
Cheers,
Eddie B.