I also agree that it looks just like a servo box and not a spar. Go to my web page and see the reapir I did on a BVM F-86 that was similiar to this. It is located in the FAQ section
http://www.crcja.org/
Or better yet, the short version,
http://www.crcja.org/faq/repairs.htm
In this cace the wing had stress cracks that also originated at the sevo box location, since back in the days this had a RAM 750, I decided to make sure it would be more than strong enough.
Turbulence
ORIGINAL: donniercjet
it looks to me as though the box for the servo is just that. not a spar just a ply box. if it is a spar its really thin one that i wouldn't trust in my jet...as for the glass crack, im no expert so i will leave that one alone