Are the basic dimensions compatible? I thought the 218 was longer than the 215, the roofs are quite different and not all have the same bogies.

After the critical reception given to the "re-numbered" Hobby 218, Roco's marketing people might be chary of producing a scale model, at least until the 215 has been off the market for a few years. That hasn't happened after over 30 years so far!

David