Looks like you're running radials all the way around (michelins in front?). Normally, the tire's air pressure requirements are different depending on the type of machine and operating weight.
If you're gonna be doing a lot of loading, I'd run 45 in front and 30 or so in the rear. You might check with Michelin on this as both under inflation or over inflation are a somewhat critical part of the tire's life.
I don't know much about running liquid in earthmover tires, but I would definitely pull a small sample to try and figure out exactly what it is. I have heard of this in farm tires though. That's another thing you might ask michelin about.
As for fiat allis parts, these guys have a pretty good inventory of Fiat Allis parts left over.
http://www.aedauthorized.com/dealer-home.cfm?org_id=67263.0