IM site has the 42' flats and x-29's listed for release. I haven't looked to see if they are the same rd#s as the first run or not.
Be careful you double check the details before you order as RC had more variations of the HO car than the N one, so you may not be getting what the pictures show i.e. the CGW version most likely won't have the correct door like the HO version.
Where are the N scale GN plywood cars?
Jason