Well all design is a comprimise but I really hate it when something that should be simple, requires a complex procedure to deal with. 3/4" sounds like a lot to overcome. If you can post a picture, perhaps we can come up with another idea.
I guess if I were dealing with this problem and had no other alternative for pump removal, I would split the tractor at the sump. Block the front wheels and support the rear of the frame rails on jack stands and wedges to still allow access to all the oil sump bolts but not allow the frame rails or sump to move down as the bolts connecting the sump to engine block are removed. Remove the radiator and disconect the battery. Disconnect the steering hydraulic lines back near the rear of the frame rails. Remove the drive shaft that connects the transfer case to the front differential. Block the rear wheels.
Using a combination of floor jack under the creeper box and engine hoist connected to the engine lift points at the top of the engine, lift the engine block up, leaving the oil sump and frame rails setting on the jack stands. At this point the rear portion of the tractor, setting on the rear wheels, will be hanging by the engine hoist and the jack under the front of the transmission. Once the block is raised enough to clear the sump, you could continue lifting the block untill you got enough clearance to remove the pump or you could shift the engine block to the left slightly to gain enough clerance to remove the oil pump. If the gasket at the block-sump union is damaged, it will also need to be replaced. This of course dosn't address the potential for damage to the bearings that could have been caused by oil starvation.
Once the pump is repaired/replaced and re-installed, carefully lower the block down onto the sump and re-install the bolts to re-join the block to the sump.
This procedure, if not done properly, is full of opportunities to get hurt real bad and requires suitable stands/blocks, a substantial jack and hoist to safely lift and support the weights involved. It also requires a good ammount of solid floor space to accomplish safely. If I wasn't fully confident I could do it safely, I would find a mechanic to discuss/look at the problem then load the thing onto a trailer for a trip to the shop. I don't recall if you mentioned how you came by this tractor, but this is a manufacturing defect requiring a substantial ammount of labor to repair with only 5 hours on the clock. If it was through a dealer, if they even remotely stand by what they sell then I would hope they would be willing to compensate you for repairs or replace the machine.
Good Luck.
