Not many on this forum to converse with, I think it will be harder then you make it sound going from HO to HOn3 as I have been modeling for some 50 years and have done it all. I would consider going to On30, much easier to scale up them down, plus On30 runs on HO track which you all ready have some HO stuff to work with it sounds like. I just returned from the NGC in Houston last month and I was very impressed with a new up and coming scale, HOn30, runs on N Gauge track, but is HO scale. Engines were being made from N Gauge Model Power engines with larger steam engine bodies being built for them, really neat stuff and can be done at 1/3 the cost of Blackstone. Good Luck with what you do, just my thoughts, and welcome to this site.
John
