Any of you ever use a 5th Wheel Dolly like this?

Blanco1, a used forklift could be had for cheap. Just check around for equipment auctions around SoCal. Even a small lift will usually handle 4k lbs. Just put a cup on one fork to hold the king pin and you're set. Might even find an electric one. An LP model might be more desirable, since it'd likely be sitting a lot.

Lyle