$500 might be a little ambitious, but not by much. 600 arabesque parts are very nice, but a non-obvious build for a european frame from the late 70s/early 80s.

Either way, I bet there's someone out there who would be pretty pumped to have this in their stable.

An older bike like this wants to be ready to ride if you want to extract the most value- if the tires hold air, air them up and get the cables moving freely. Also it'd probably be worth the $10 investment in brake hoods- the standard cane creek brake hoods fit these levers quite well and add a freshness to the bike.