I haven't been able to find even a mention of motor mounts much less anything for sale. What does everyone doing about motor mounts? 

Engine front mount should be a trunion style which is behind the harmonic balancer supporting a bolted to the block bracket, or the engine front timing cover. The rear mounts should be on the flywheel housing. Both mounts will have rubber isolators incorporated and you may have to make or modify something to work.

The circular gouges you have are probably from a prior water pump losing it's bearings and the fan blade getting into the radiator core. Sometimes bad, sometime superficial and can be left alone. A good radiator shop can advise you.

I am already having the radiator recored. The shop vatted and tested it, and it's time for a new one. I'm saving the old core and the tanks. The newest catalog that had the core in it was from 1990. It took a few calls for my guy to find one, but he did.

I understand. Many call them "cushions" also so can get kind of confusing. In many instances you can easily make your own with a hard rubber sheet, or pucks from Mcmaster-Carr. They are not show in the Minnpar website that I've seen.

Having the vertical milling machine and a lathe will help you tremendously in fabricating anything you require concerning engine mountings. You'll like the HD6 once operational as you can get a lot done with them being not too large, and certainly not too small for most any medium task.

Easy enough to move behind a one ton truck on a gooseneck trailer makes them very versatile. Although modern CTL's have largely hurt their market share in the segment, a well maintained small dozer is still very prized among farmers in this area.

This is a dozer that my dad bought long ago, and I am bringing it back to running condition for the reasons that you mentioned. He poured water in the cooling system, the water manifold cracked, and the dozer never ran again aside from a minute or two just to crank it. He had taken the water manifold to be brazed, and the guy threw the casting away. Someone else came along and took off the hood and valve cover and left the engine exposed for months. The rocker shaft is completely rusted, and the old engine is seized. What I would do to hear the sound of those energy cells again. The 6000 is going to be an upgrade, so I can't complain.

The milling machine has already been indispensable. I bought some lifting eye forgings from McMaster-Carr and drilled and tapped them on the machine. I have the engine lifted by some webbing around a boss behind the fan on one side and from the eye screwed into a head stud on the other side. It's holding up very well.

There are some threads on removing the radiator. On this unit, the radiator will not slide out the front any way that you try because it is wider than the grille. I was able to pull it out from behind without dropping the hard nose by removing a bunch of things. The fan and several brackets had to come out, the valve cover had to come off, and I had just enough room to tilt the radiator back and slide it up and out at an angle. I had maybe an inch of clearance and did not have to remove the water pump. When the radiator goes back in, I will have the old engine out.

Thank you