The turntable (or dolly) was purchased for a miraculous £39 plus postage on ebay and assembled in the bottom garage. I then cut away a step and put in a concrete ramp. I found, initially, that the floor locking mechanism slipped, so put holes in the concrete floor to anchor the dolly with steel bar.
Today I tested out the concrete ramp for the first time and the bike launched effortlessly up to the upper workshop and out the door, up the garden and through the new gate, which I wanted to test for fit. I adjusted the quick-release on the mirrors so that they can be folded in for this.
I turned the bike round (having turned the dolly round ready, because the side stand tray has to be on the left) and took the bike back down the garden for these photos...in which you can see the bike driving on to the dolly, the latter being turned around and pushed sideways out of the way. It is a terrific piece of kit.