Maybe I am missing something but this seems like it's being made overly complicated. If the existing tank is bad, and if it really takes forever to get a replacement built in, a simple device like an "extend a stay" hooked to an LP tank you can get at any grocery store will work. I am not sure what RV you have but I see LP tanks of varying sizes everywhere. Are you saying you can't find a single one to replace the existing tank? Even if the mounting hardware had to be fabricated by a welding shop, it doesn't seem that hard or expensive,