Another major milestone! The mower now moves under its own power. Could not do too much testing since I had to ride it standing on it but I took it for a spin around the driveway. Moves smoothly both forwards are backwards. What I did to get it going:
1. Ran it forwards and backwards with the dump valves partially open and wheels off the ground.
2. Ran it on the ground same way. It moved but slowly.
3. After moving around that way for a while closed the dump valves and it moves normally
No moaning and groaning and (so far at least) no leaks!
Will do some more testing when I put the seat together and get all the stubbed out safety switches either wrapped with electrical tape or (hopefully) properly connected.
Called it a day and popped open a Cold Corona - Cheers!