Yes it is possible to do, but thats not the real issue, its how easy is it to do, and is it worth the effort.
the biggest problem I see with that is actually finding a replacement potentiometer for that specific radio. I have never seen them for sale anywhere so this may be a hard thing to find. Then you would have to take the radio apart, unsolder the old one off the circuit board, and then soldering on the new one. All this while not screwing anything else up on the radio. Then put it back together and hope it works.
saying that I do not feel that it is worth it at all. If you really want to keep the factory radio, your best option would be to call a few junk yards and see if you can find a complete unit. Or you can just replace it with an aftermarket radio, which in my opinion is the best choice