Everyone agrees "Skinny 4" is an early version around 63 and then those later adds show what seems to be the same insert. My bet is that the adds back then weren't always accurate reflecting the exact dial/insert version being sold in a given year. Perhaps service manuals would be a better indicator. Again this has been a great post, very informative and has led to another helpful thread over on VRF Hats off to you, maybe this will continue until all the known versions can be placed is chronological order.