It's an "E6-B Flight Computer" -- and came apart when I tried to remember how use it
View attachment 980396
The aluminium Degree wheel should be glued to the transparent plastic disc and both seated in the Variation / Wind Angle holder below. Looks as if the 45 year old glue wasn't too good. Maybe I should use Gorilla Glue and it'll be good to go flying again.
View attachment 980397
Click to expand...