Steve and Brenda,
Too Fun! I just drilled through the bulkhead for a battery switch near the landing gear switch - just wood. At least for mine there was not any concealed spaces for wiring runs, etc. I cant answer for the central space directly between the basement and the front compartment.
I certainly understand the stuff that gets accumulated in your RV. I put one on consignment and it took two truckloads to get all the stuff out. We never take anything out, but continuously end up putting stuff in! Between Camping World and the other stores we're always bringing stuff home for the "RV". In fact I have two bags of stuff laying in the garage waiting for the next trip to the RV, and Dory brought home a blender yesterday she found "on-sale" for the RV. Oh-well
Margarita Time