According to the catalog its "New Tooling", " Today the American Steam Railroad Foundation is embarking on a program to bring 2100 back to service yet again. Lionel has worked extensively with the organization to measure and document the T1 to bring you the most accurate model possible".
In addition, it is suppose to have a Kinematic drawbar, which Lionel has only been able to add to "all new" locos like the S3. Anything using "existing tooling" has no provisions for this new drawbar.
This new one "should" make the '89 version look like a postwar piece.
Of course there is that whole disclaimer thing, just in case they decide to merely add a couple rivets or handrails to the "89 tooling
