This is an interesting idea I hadn't thought of before!
You already bring up the issue of being understaffed, how that's led Graff House and New Hall to remain primarily closed, and how that might affect PHM. I'm actually concerned more about the current status of NPS within the federal budget, with ongoing debates about how much federal spending should go towards parks and other cultural sites, plus the current administration threatening to close or at least downsize several parks.
Do you think there's a case to be made for the feasibility/appropriateness of this plan despite those debates?
RE: Another Solution for the Philadelphia History Museum?