Mine fell apart last week, so I thought I'd give this suggestion a try. I had to open up the clip by pushing it over some 10x20mm flat bar and squeezing it in the vice (the clip on the left in first picture).
Then I cut two rebates on the ball...
There's no economy gain in removing the prop because the rear wheels are still turning the rear diff over. You'd need freewheel hubs on the back to see a benefit.
I'm not sure the tyres need to be identical all round- isn't the viscous coupling...
Yesterday I dragged mine into our garage as it is currently immobile due to a broken gear linkage.
I have a cheap hand winch bolted to the workbench for this purpose. The drive slopes up slightly to the garage and there is a lip of about an inch...