Here is an example of a New Hampshire Red from a show breeder:
The easy difference to me is the golden hackles (obviously many variations in other features as well like body type). The hackles are the most obvious when glancing at a bird though
Their coloring is not correct for New Hampshires :) They have the typical rusty red of a Production Red or hatchery-quality RIR (which I call Production Reds due to their extreme deviation from the breed.)