Thank you all for your help. The bike does fit me and I had it built up with modern components for a while, but my wife's been having to deal with some medical stuff so some of my collection has to go to help pay the bills. (The brifters, newer wheels I had on it, etc. will fetch more individually than hung on this frame so that's why I put on the original RX stuff.) Considering the value vs. the hassle of selling it on Ebay , I guess I will just toss it up in the rafters for now and deal with disposing of it during the next garage clean-up project (maybe it will have gained some value by then).

Bianchigirll is correct on the history. The interesting thing about the bike is the "Avenir Equipped" logo - maybe the original saddle, seatpost or bars were from Avenir, because there isn't anything on there now (it would be kind of weird if they did the logo for those mundane pieces though).

T-Mar, the SN is 90A8278.