ConducTTor wrote:Model Railroader is the first that comes to mind.
I agree. In my view, Model Railroader is still the primary magazine, especially for beginners in the hobby, and an article about the GuiTTar Case layout will do the most to promote awareness of TT's existence and validity among the model railroading public. I hope you find the time and energy to do this!
The other option is MRH, their advantage is that the e-magazine is free, which may help draw in younger modelers who don't want to pay for paper publications. But then, MRH has already indicated that they're inclined to promote TT, so Model Railroader seems the most promising venue for your efforts.
Go for it!
Sometimes you win... sometimes you learn.