sorry, that's a double gusset and drop outs are different
my bad, i didnt mean to say that was definitively it, just that it looked like it, and yeah only a single gusset, like a mkI burner.
Taking on board rodgy's comment could it be a Huffy?? I know the pre 84 ones were gusseted, it may not be the popular pro thunder, but as i've found out there are a lot more huffys out there than in the bmx museum