With my Holdsworth being cut apart and brazed back together under [MENTION=381793]gugie[/MENTION]'s skilled hands, I have been without a 650b bike for a few months. It turns out this is a very good way to determine whether you like the whole 650b thing; and I found absence does indeed bring an old cliche to mind.
So I took this old Bottecchia frame --early 1970's, either a Professional or Giro d'Italia model, I think they were the same frame with different components-- and built it up with some more or less correct parts, and some later stuff. Here's what they looked like in the sales literature 45 years ago:

Weinmann ZAC19 rims, 42 mm Hetres fit under Bluemels Lightweight fenders. The front brake is an Altenburger Syncron, an early version of the dual pivot sidepull. The rear brake is a Tektro 559 and even so I had to make a drop bolt for it. I believe there is a longer version of the Altenburger that will fit there. Mounting the Velo Orange rack on the fork was a mindboggling pain in the neck. To be fair, I guess that's the fender's fault.
I think I'm going to have to switch the fenders to VO aluminum ones so I can put a light on the rear fender. For now, there's a Planet Bike dynamo headlight on the handlebar, but I'll probably change that, too. I don't like having the light on the handlebar.