Bob,
Congratulations on your eBay find! The bike looks very elegant and super clean, and for the price it's like finding it in the street. I'd guess you're probably close on the date. I don't know when Peugeot started going lug-less on their frames, but that should give some clue. I have a catalog from (I think) 1986 that I can check. One would think some former dealers out there could say right off. Maybe when it arrives you could provide some more details. I get weary of reading only about super expensive Italian stuff, and a little variety is quite welcome.
John Hurley
Austin, Texas USA