It would seem there could be a tidy profit in recycling this stuff.
As prefab pieces it is worth keeping in orbit, but space vehicles are so specific and specialized that I doubt much of it could be used as-is. A space-baced smelter and casting platform could use it. If NASA had kept main shuttle fuel tanks in orbit, we could have a large habitat there by now.
A smelter or something. It would probably make sense to start the engineering on the ground with an eye to utility to future purposes as well as the immediate utility. Some sort of “modular” system whereby, for instance, as you pointed out fuel tanks could be used for construction after lifted into orbit.