There were two basic Chief designs, the pre-war (often called the "65", or 65-C or 65-CA; for the earliest ones, the 50) and the post-war 11AC. So when looking for plans, watch for it if you have a preference. The pre-war is harder to find. Not done that much. I have a 1/2A Texaco plan for the 65, but it is not rib-for-rib construction. I could get you an address but not copy...the guy who did it signed it to me and clearly wants a bit of return on his work. I think I paid him $15.

Jim