Servo Mounting - Slim Wing

I have just acquired the Fly Fly Glass/Compo 3 meter glider. Not an expensive one but good looking and well built. (Want to try silent flight again!) Except the accessories are crap. But I knew this beforehand after reading a rather lame post on RCgroups where it mostly went off subject..

My problem.

The servo holes for ailerons and flaps in the wing are small and the flimsy plastic servo covers which you have to cut out would need mounting blocks glueing on to them. I have tried Hitec 5055MGs in the recesses and they would fit. but I can't seem to find some sturdier servo covers for these Hitecs.

I could make some covers out of ply, I suppose but then the covers woulds be fairly proud of the wing surface compared to dedicated plastic covers.

Any suggestions? Multiplex maybe or............