I don't have an answer to your question but I do have a suggestion if you're open to one.
Whatever the thickness, you might want to look at the combination locks at this link.
I put them on mine and they're absolutely great!
You can lock/hide your spare set of keys for the entrance door in one of the basement compartments and still be able to get at them if you lose the main set simply by using the combination to get into the basement. I also like them because I can give a repair shop the combination if they need to get in and then, once the work is done, I can change the combination. The combination is any 3 digit number you want so it will be easy to remember.
If you are like me, every time you want to get into a locked compartment, you don't have the key with you and you have to go get one. This solves that problem.
They are no easier to break into than if you had a standard lock.
They install in the same manner as if you were replacing the OEM style lock.
I don't work for them, nor am I receiving anything for this recommendation.