If you work out the numbers, HO gauge track is about 32 inch gauge in O scale. O gauge track is actually 5 ft in O scale 4 ft 8 1/2 inches for prototype. So the 32 inch HO gauge is about 4 inches off 36 inch which was the most used common carrier gauge in the USA. O gauge track is about 3 1/2 inches off scale for O scale.
The Bachman models are based on smaller 3 ft gauge prototypes in many cases.
While the HO track is too small, it is not much farther off than the O gauge track most of use.
So I think you can use HO track gauge to represent a believable narrow gauge common carrier. But you probably want to change the tie size and spacing. You want to use Narrow gauge O scale trucks, not HO trucks. You want to put O scale details on the locos you convert.
So give it a try.
