Found a serial number under all the grime: 90798 1283. This would fit with the August '83 date stamp on the derailleur. Also, seat tube appears to be unbutted with an I.D. of 1".

I have no illusions of this thing being some kind of buried treasure and have no interest in establishing a value. I'm just curious because it's a brand I've never heard of. Apparently no one else has either.