Without going in to the question of legality for the Maryland leg of your journey, do you have a license/permit from a state
that PA honors? In PA you may only transport handguns unloaded and to a very limited list of exceptions. You may transport
or carry loaded, in your vehicle, with a permit/license from any state, but if you conceal carry you must have a license/permit
from a state that PA honors.
Unlicensed open carry is by foot only, and Norristown is quite a walk from the Maryland line!
I figure we can cover any other questions once we clear these hurdles.