i think you should't "rename" the 3.41 as a 3.51 version because if you can upgrade and then something is wrong you wouldnt be able to go back to an original 3.50 version.
you can "rename" it as a 3.50.the system will allow you to update and you would be able to reinstall a 3.50 original update because it allows you to install again the same version you had installed.
i'm sorry because of my english, im spanish and i dont know if you catch what im trying to explain.