Early A door lock conversion

Can you remove the tail gate cylinder and take it a lock smith to see if it can be made to work with your new door key?

it is the large cylinder just like the doors previously had ....I am thinking I might be able to find a single with a want ad. The problem is usually finding a set matched to the ignition, but a single from say a passenger door might not be as challenging to find. I am totally cool with two keys because that is really the same as any other car.