I love old posts- inquisitive minds who think what I'm thinking are looking for sources of code 172 Nickel silver rail to do some handlaid track, and "other things". I find it interesting that after 25 years, no one has still introduced an O gauge version of Marklin track.
The reason for using code 172 rail are obvious- but if a Vision Line Challenger can run code 148 track, I guess I'd be the person to see if it actually could.
Geno