After letting the hyd. filter bolt soak with penetrating oil a few days, I tried again last night to remove it, but succeded only in rounding-off the head. I don't think there is room to get a drill in there unless i can find a drill bit at least 18 inches long. Would also need a center punch about 18 inches long to center punch the bolt before drilling.
While sitting on the ground next to the thing, and thinking about the next move, I found myelf looking at the fuel filter, or rather, where the fuel filter should be. There is no bowl and no element, and the remains of the filter housing have been bypassed with a piece of steel brake line tubing. So the previous owner was running the thing with no filter. i suppose an inline filter would work, but I'm not sure how easy it would be to bleed the air. I have installed many inline filters on small gasoline engines, usually clear plastic filters so that i could see what was going on, and it seems to me they always have a bubble in them. Plus, the shut-off valve is incorporated into the factory filter housing, so I would need to rig up some sort of shut-off valve.
Sent an email to Valley Power to see if the bowls are available.
On a happier note: I am always picking up bits of steel scrap in case they will be of use in future projects. One bit i picked up is a 3 foot long piece of I-beam with 5 inch flanges and a 12 inch web. This will be drilled and then bolted to the front of the tractor, web horizontal, for a front bumper and also for mounting weights to.