There IS good brass out there . After many years of very few models ,PSC has turned out some excellent HOn3 .Some older brass ,like Westside and Balboa engines can be modernized with better gearboxes and motors . I took a very old Balboa T-12 and ,with new castings and drive ,it looked and ran great as #175 .The 2-8-2s generally run well ,simply because they have size and weight . The smaller engines will run ,only if the wiring and trackwork is very good and-this is important-that code 70 rail is used(it has better conductivity than smaller rail). I have a very good friend who has abeautiful HOn3 layout that does not run well at all .The problem is he used code 55 rail ,not enough wiring and bad switches . These smaller engines have a lot of trouble with bad track or poor electrical connections .
The reason that an HOn3 plastic model has not been turned out by Athearn or Kato is that with only 2 to 5000 modellers in HOn3 ,the volume is not there to profit from such a model . I know people who are in the model business and to cut the hundreds of molds to make such a model is a long and expensive process . John Parker of San Juan Car wWorks is about to release n On3 C-16 plastic kit .A lot of other model makers will be watching closely to see if he will be able to profit from this line .