That is all good research. It is too bad there is not more info available to help determine. Right now I think the date is indeterminate and I will leave it categorized as late 1960's on my page. My reasons are that the head badge is most similar to the 1960's versions I have shown. Also the world champion badge on the seat tube is clearly seen on the 1967 bike shown in the barn page. I have not seen that badge on earlier bikes. Also, that headset, especially the bottom cup could have been used later. The 1970's bike shown appears to have the same unit. I think that paint is not a clear indicator of year of manufacture. I am open to persuasion if better info become available. Keep up the good work!