I'm going to try to pin it down, we'll see if the date codes offer anything concrete: 1967 Model B. I would say earlier based on the post, but I think if it were early 60's it would have Universal brakes, a cottered Magistroni crank and a Cinelli, not Campy headset. Also I'd expect Cinelli steel bars and stem. If all that Campy stuff is original I would say as late 60's as possible without the holes in the lugs, so 1967. Don't be put off or confused like I was by no oiler port in the bb, the Model B never had one.