And there is your answer. But do join us - plan to do your own work.
If there were any profit at all in what you propose, somebody would already be doing it. There have been locomotives done in Proto-48, but as far as I can tell, none below the 2 grand point.
My personal opinion - and most will disagree - is when treads get below .150 width you are asking for operational problems. I run .172 tread width, and model in 17/64 scale to get the proper track width.
