Those signs, regardless of size, are always broken.
When I first got my PA permit, the only thing I was told was, dont go in the state parks, and dont cross the river into NJ.
I still have yet to see any "guidelines" from the counties that have issued my permits, and they usually dont offer advice.
About the only places you cant go are state and federal courthouses (you have to check your gun), schools (but theres a "but", the way the law reads, there is the ever present "any other lawful purpose" clause, so maybe/maybe not), some state parks, or even areas of some state parks, depends on hunting seasons, and up until recently, maybe or maybe not, federal parks. Probably ought to stay out of federal buildings too, unless they let you check your gun. Post offices are an ongoing debate, and they have conflicting cites, so you have to decide what you want to do.
Private property is at your own risk. If your doing everything right, they'll never know, unless something goes wrong and you need your gun, then you'll be glad the sign was broken. Personally, I ignore the signs and go about my business.