Bill.
Just taken a series of pics under the Wyoming.
The scissors action runs on a piece of very thin steel screwed to the floor. The rear runners extend from the very end of the chassis. The front ones are not mounted to any part of the chassis , only the floor but again with thin mild steel strip for the scissors action.
Maybe not all caravans are the same. Personally I would not use the steadies as a primary support but just as steadies with the wheels and jockey wheel taking the main weight.