Who painted the frame/added the downtube decal?

That shade of blue and the lack of the typical vertical seat tube Trek decal make me think this was a custom build. There were a number of such custom frames built for friends of Trek framebuilders. Last may, I built up one of such anomalous frames (sport touring geometry, but with Columbus SL frame and fork and Campagnolo dropouts/fork tips) with Campagnolo 10 speed for my dad. The gentleman who sold me the frame (then built up with Suntour BL) had received the bike in 1982 as a gift from a friend who worked for Trek.

I have seen two other "blue mystery" Treks around Madison (WI). A Reynolds 531 touring bike (essentially a 720) on Craigslist and a Reynolds 531 sport-touring bike that is typically locked up outside of Ag. Hall (sigh).