In this version, didn't Nathan actually show up in the first act (albeit in the last few moments before intermission)? I know (from the recording and liner notes thereto) that in the original incarnation of the show, he showed up earlier in the act, where we saw him hobnobbing with the corrupt politicos, in the song "What's Wrong With That?," which now happens after he finds Rebecca and David, and he and Rebecca both take part in it (which seemed a little weird to me--worked in a way, and didn't in a way).
They did a good job in any case, and I'm glad to have gotten to see it (especially having missed the production of it a few years ago, directed by Linda Leonard for the J Players). To me, there are still problems with how the whole story and all the characters hang together, but it's well worth seeing and hearing. Now if Mr. Jones and Lyric would just turn their hands to NICK AND NORA. Just way too much fun in that score and concept to let book problems and a Broadway flop stand in the way.