So I moved the access to over the top of the pump . I can reach all around the pump by lying on a piece of wood placed over the storage area. Hoses and fittings are accessible . The fresh water tank hose clamp has minimal clearance between the bed base and the clamp. The base of the bed storage area is level front to back and side to side.
Shims provide a solid base and closeout around the sides.
Aluminum stiffeners are recessed where needed an adequate amount to permit intersecting side pieces to also use stiffeners as mounting brackets. The lift mechanism consists of two 90 pound twenty inch gas springs with an eight inch travel. Mounting to the wood is via one angle bracket and one straight bracket for each spring. The mattress board by itself is easily counter-balanced by one spring. Plan to put in two as the mattress adds enough weight that the second one is needed.