Agreed, SA hubs aren't bad, and about 90% of the time they aren't at fault if shifting isn't right.
I just got a red '70 Columbia Sport III with a rear rack to go with my turquoise one. Mine was cheap and heavy too, but wouldn't shift. About ten minutes of lubing the trigger shifter and adjusting the shift cable fixed it. Perfect now. It's a stately ride, and though I haven't checked the number of teeth on the chainring and rear sprocket, the ratios are about right for a casual rider.