Cargo door repair?

Those cargo doors are styrofoam core with a thin wood/plastic film,...this is what I did: The 6x8 3/16 aluminum plates cost me $20 to have cut at a machine shop, I used Sikaflex adhesive caulk for the adhesion, the screws were just to hold the plate in place while the adhesive cured. Been 3 years now, no sign of failure.

https://lh6.googleusercontent.com/-apqHocMlEsg/TDJAIo6Z4DI/AAAAAAAACMg/0H60GX3lOZI/s640/IMG_2899.JPG

Regards
Gemstone