Thier are several places, I think at least one on the East coast. I got a reproduction for my 66 from The Bird Nest, Port. Or. as I had wore the original one that I bought in 66 out. You can call them at 800-232-6378 or go to their web site
www.tbirdparts.com This is a job you will only want to do once, so I would put in a new core---I finally had to replace mine a few years back.