Verified answer

Pennsylvania has a notoriously weird and ambiguous weapon law (see link below). But from what I can interpret, they're pretty lax with regular knives. I used to camp up there, and both sheath and folding knives never were a problem with the camp staff.

The law does provide the following defense:

"possessed or dealt with the weapon solely as a curio or in a dramatic performance"

I think that pretty much covers medieval weapons, provided you keep them in you house, or use them for dramatic performances. Obviously, they are not valid for self defense (that is not a "curio" after all). Self-defense is not actually a written law, it's an defense you use with your lawyer when you are on trial for assault/murder.

Individual cities frequently require permits to do plays or reenactments out in public where weapons are used.

I do believe PA has a law where you need a permit to carry a concealed battle ax