Something that would be in Rapido's domain, that could be tempting (not really in my timeframe-region, but I could always claim that an AB set had strayed through the tunnel at Sarnia) would be the Fairbanks Morse (and-or Canadian Locomotive Co) C-liners used by CN and New Haven (which appear to be their 2 favorite roads).
In addition to the real roads, they could issue "nostalgic" paint schemes from the early days of N scale, when Atlas (or AHM in HO scale, not sure if they also marketed one in N) issued them in any and all paint schemes.