I tell ya, the door dolly has been invaluable. I had each door on and off a dozen times getting the jam right. I have been able to move the doors all around with ease and now are stored in the basement till I am ready for them.
The wonderful thing about adjustments it, they go back on the correct height.
It took me about 2 hours to cut up the parts and weld them together. The time and difficulty they saved was invaluable.