Thanks guys. Daver I threw away all my sketches as I finished those parts. I can tell you the steel cabinet is 47-15/16" wide X 24" deep to the outside of the sheeting so 48" wide plywood would just overhang a bit and the 3/4" pine would fit around the outside. The steel cabinet is 29-1/4" high plus 2-1/4" for the top and 5-3/8" for the casters, 36-7/8" overall seems good for me at 5'-11" tall. I made the frame from 1-1/2"X.083" tubing and 1-1/4"X.083" tubing fits pretty good inside, I tack a small washer to the top inboard end of the 1-1/4" tubing so the extension table ends do not sag much at all when extended, the ext tables (wood top) are 14" X 25" it allows for more work area when needed, but the frames push in for storage. The only tip I can really share is to keep the frame square when building it, it will want to move around when you weld it up. I also tacked in some diagonal bracing before final welding, then cut them out after some of the sheeting was tacked in place.