OP, it's not really that hard, but I think you're in a catch-22. Yes, your FIL can just hand off the guns according to Pa law, but that (I THINK) only applies to this if you are both Pa residents. Once your wife moved out of state the Fed got there grimy little hands involved and now you need a transfer.
My advice, for what it's worth, would be to find a reputable dealer in your FIL's area and take the guns to them. They can probably advise you and handle any transfer. Yeah it's a PITA but really not a huge one.And if you transfer them through an FFL and something is wrong, it's on the FFL not you.
For the record I am not an FFL and just speaking of my tiny bit of knowledge regarding this issue. If you decide to use an FFL I can give you some names in my area if that's where your FIL lives. I have a VERY short list of FFL's that I trust and they won't steer you wrong. Good luck.