Interesting indeed. After reading this i ended up opening the covers of 4 neck-through Wings.. the result: '79 Eagle was Yamaki with hand written numbers in the cavity and on the cover. The other 3 ('80 Hawk, '80 Eagle, '81 Eagle) had no name on the PCB and numbers stamped in the cavity and on the cover. The Yamaki PCB was slightly different from the other 3, a bit narrower copper strips to guide the electricity and also layed out in a different style. Took a pic of 2 boards next to each other but it's still in my phone. Now i'm curious if all pre '80 Wings have Yamaki boards.
I think the numbers on the inside of the control-covers have to do with the production method for the guitars.. on the inside of the cavity in the guitar itself you will find the same number. The parts were probably hand-made (so little variations could occur) , then taken apart for painting, then re-joined for assembly and the number was used to figure out which cover belongs to which guitar.
Crusty, i'm still working on the Wing-specs but it's a slow process since it's a maze and i don't have a lot of time at the moment. Also: a certain series of the early Hawks ('78, '79, with the jack-input on the front of the guitar) come from the same manufacturer as the Ravens.. plastic control covers in the same shape, the same shape trussrod-cover with the sharp points, etc.
Greetz!
Hans.
Here's the pic, the PCB on the right is from the Hawk which doesn't have push-pull pots. The Yamaki-board is a bit messed up as you can see.. a previous owner replaced one of the pots and ripped out the original pups.. bummer.
http://img218.imageshack.us/img218/2886/dsc01017hc7.jpg