It's always something, right? They do make different depths but when you get as thin as the plastic is, they might be too thick as you mentioned. It looks like they should hold, as I said, hope it holds for you. I just used self tapping screws and put a dab of clear gorilla glue on the back after I ground off the excess. I hope mine hold too! After all the work I have been doing, I hope to never have to take them off again!
FredD