Thanks for the welcome! I've already found this forum is a wealth of knowledge...lots of experience and advice to be found here. I'll be sure to check out the vintage bike section.
Regarding my bike - an interesting question. I've always believed it was a Norstar, given that's how it's marked, but I can't find any record of such a model. The description of the Corsa sounds very close, yellow with Simplex derailleurs, Weinmann 610 brakes.
I don't have much to compare it to, but I always thought it was a wonderful bike and I've certainly logged plenty of miles in the 30-odd years I've been riding it. It has, over the past several years, fallen into disrepair and really, that's what brought me to this forum. I hadn't realized how difficult it would be finding replacement parts, but I've slowly found what I've needed - ordered lots of new parts and I expect it will be fit for riding again by Easter (I hope, anyways).