Great detective work, Hart!  However, I think those factors--especially the TWA thing--are likely slipups on Jim's part rather than indicators of the time.  Having DM take place in 2000 or 2001 would mean that SF took place in 1997 or 1998, and therefore that Harry was born around 1972, a full two years before a young David Copperfield adopted that stage name.  On the other hand, the airport security in DM does feel pre-9/11.  Hmm.

Poor Jim we pressure him to write faster then pick apart at the continuality.