Gold Crown 1 Early Models

Does anyone know or have a pretty good idea of what year the GC1s changed from the full length rail extrusion to a series of six inch extrusions?

Thanks for any info.

jfred

Got a reply from a good source that he figures about 1963. Back in 2012 when I was soaking up all the Gold Crown info I could find, the evidence pointed toward my GC1 being a '63, as well. So, unless something else pops up, my case is closed.