I'm actually flying into Paris on 4/11 and I'll be there staying with my friend until 4/16. I'm taking the Eurostar to London early in the morning on 4/17 and flying out of London back to New York on Sunday 4/19. (So you could pick me up at St Pancras at 9 am?)

NY->Paris and London->NY actually ended up costing about the same as a round trip New York to Paris flight since I saved on only buying a one way Eurostar ticket.