The law is silent on open-carry in Pennsylvania, so there is no citation to show you.
I won't bother, unless you ask, with citations for concealed-carry, seems you are already aware of the law, and you are correct. You may carry concealed as well as transport in a vehicle (OC or CC) a loaded firearm, with a license/permit from any state.
OC is PA is *not* just for residents! The one distinction is that a license/permit is required for open-carry in Philadelphia.
Last, unless you have a PA LTCF you are prohibited from carrying in the 1000' Federal GFSZ.
Enjoy your visit!