7 months later:
I posted back in July that I'd gotten this bike but have only now gotten to taking a decent set of "after" pictures. I found it in a typically neglected state - gumwalls melted and fused to the wheels, grimy, badly dried and torn B17...but it was mechanically sound and the right size. My goal was to get it rideable quickly and to pretty it up while keeping its original lines and dignified stance.
On inspection I found nothing had to be replaced other than the pedals, brake blocks and tires so I scraped the muck off rims and cleaned them up with Evapo-Rust baths and copper wool. I serviced the front hub and just oiled the rear - I'll open that sometime this winter for fun and curiosity. No major truing was needed, so new cloth rim strips and Panaracer Paselas finished the wheels.
I got some cheap pedals at my LBS but the original pedal bodies were fine so I cleaned them up and used the new rubber blocks on the old bodies. They were a bit narrower than the originals so I used small washers to compensate and they are a great visual fit.
I haven't done the bottom bracket yet, but the chainwheel spun fine and had no play, so that's also been moved to the "I'm bored" winter activity list. I got a new chain, but the old one seemed sound so I use Evapo-Rust on it and it came out great. I did clean up the headset, even though it really wasn't bad.
Put salmon Kool-stops on the brakes, which had good cables and then lots and lots of chrome polishing using copper wool, brass brushes and frame cleaning/oiling/waxing.
I treated the B17 with Proofide to get it supple, then I stitched the tear (it come up from the side almost halfway to the front-back centerline) and laced the sides in. It looked OK, but it was quite flexy on the bike and the surface is too rough from all the cracking so I have it in a bag until I feel like trying to tighten it. There's a bit of tearing at the nose rivet so I don't have much hope.
I found a hardly used, brown B66 on eBay that's perfect:
That got me to the "ridable" state, and the rest was about the details. I snagged a replica pump and vintage "pleather" saddle bag at Old Roads in Cambridge, MA. A local shoemaker replaced the dried and torn straps that are sewn onto the flap.
I happened across a NOS Sturmey Archer dynamo tail light at the LBS that I retrofitted with an LED and battery from a cheap book light from Walgreens, and I wrapped the kickstand with twine and shellacked it.
Next came shellacked cork grips, even though I have original ribbed bullet grips. I like the aesthetic and the feel. I finished off with a retro-style 3-led headlamp mounted to the Heron bracket.
It's a pleasure to ride my Sports, whether I'm going a few blocks to the grocery or 20+ miles along the shore on a family outing. I loved this project - I've been working on bikes since 1973, and while I feel like I'm pretty skilled and knowledgeable, I want to thank everyone who has posted in this thread and especially those of you who are so generous with your time and sharing. I've learned a lot from you.
