Write and ye shall receive. Ken "Why would someone devote a website to an obscure tire size?" Stagg left a very useful comment:
"You can fix the large gap between the tire and fender at the bottom bracket with a wine cork and a longer zip tie. Cut the cork to the proper length, drill out the center and thread the zip tie through it (both ways). I did this with my Heron conversion but haven't taken any pictures of the detail yet."
It's simply a brilliant idea. There are so many good aspects to this mini-project:
1) It involves wine. Luckily, I had just openned a bottle when I read this comment. Even more luckily, I "spurged" on a $12 bottle of wine, which means the cork is of halfway-decent quality.
2) By moving the fender back, I can access the kickstand screw with my wrench and have no problem tightening it.
3) The fender looks normal now!
After removal of the kickstand, you can get a good idea of the small space.
Then I drill a hole throught he cork. Interestingly, this is the only use of a power tool in the whole bike building process.
The cork is installed.
And the finished product: