So I was going to say, "I think the fork is a real paramount fork, because the eyelets don't match the rear, and schwinn probably made as many nervex forks as all other makers combined".
I was going to point out that Raleigh made a ton of these fast-back type bikes in 1983 and 1984, HOWEVER, to the best of my knowledge, NONE of them came with nervex lugs, and they used Gipiemme Dropouts:
http://www.bulgier.net/
Many of them came apart, too. The fastback seat-lug attachment was done by several custom builders in the 70's, but to my mind, is an 80's thing.
On the other hand, the nervex head lugs are a 70's thing. By the 1980's, almost nobody was willing to put up with those lugs in terms of all the finish-work that had to be applied to make them look nice - in the 80's IC lugs were the norm, not Nervex.
So it may or may not be a Schwinn, But it certainly is an anachronism.
- Don Gillies
San Diego, CA, USA