I'm MR'ing thru PHL that weekend and would welcome some company. I arrive v late Fri night and leave v early Sun morning, but am free all day Sat 21st. Haven't booked accomodation yet but will prob stay downtown rather than at the airport.
Happy to make arrangements around you, otherwise I'll just meander around PHL for the day on my own doing the tourist thing.
I'm currently in the UK leaving Thur 19th. I'll PM you too.