Those replacement wheels are either homemade or they were made by a local hobby store/machinist and are likely one-offs. You should be able to get the proper replacement wheels from Hennings.
Your engine also needs replacement headlight holders, as there should be a cast headlight holder on each end of the roof. Hennings likely also has this piece.
I would replace the springs and brushes also, as the original brushes are not carbon and will cause wear to the armature and the original springs likely have little spring left.
The set was first cataloged in 1928 and was sold in 1929 also. The set was sold in 2 configurations, the 1347, which you have, contains a 3115 engine, which has the track trip reverse unit. My set below is set 1387, which features a 3185 engine, which has automatic reverse.
NWL
