Great discussion since I have to fold the wings every time I fly.
I like Skypirates idea on photo 21 of his Album.
What ever the design is, I feel the dolly needs to be pinned to the fuselage like Jerry Tex did to prevent a real bad day if it ever fell off with the wings folded.
I am hoping Larry can get a photo of his friends design since I have heard that it may have a lever arm that both raises the tail and is also used as a tow bar.
I envision the the Sky Pirate design that straddles the tailwheel in a near horizontal position with small wheels to roll it in place.
Then pin it to the rear towing position, then pull back on an approx. 4-5 foot long bar with a tee handle to raise the tail, then pin it to the front tow position.
At some point when raising the tail the dolly will transition to the castering wheel. Since my hanger floor is gravel I would use a large castering wheel.
The design challenge is to get the dolly to break over center so it will stay in place till you get the second pin in place and then have the tee handle end up at the appropriate height for both raising and lowering and moving the airplane.
In the mean time I designed a simple, fool proof quick drain at the header tank that only takes a minute/ gallon if I need to and is very useful when you need to drain the fuel system.
Herman