I have a luggage rack that came off a folding bike with 20" wheels. I suspect it would be a much better fit than the rack you have. You can have it for the cost of shipping, send me a private message if you want a photo or something.
Thanks for the kind offer. This is not in the way of anything like it would be on a regular bike. If I were worried about it looking funny - well, a jogger laughed at me this morning. I don't think dialing in the fender line is going to make that much difference.
I put SPD's on it and lengthened the boom again. The boom is as far out as it will go, to its "L" and min insertion mark, and still feels too short, even though I'm a "M" sized person. I'm marking that down to the seat being all the way up. I'm going to switch the pedals again. These are simple ones, not 520's but some old equivalent, and even though clipping in is way easier than the big Velcro straps, I don't like how easy they float. I'm going to put on T400's, which have a rubber pad around the latch which still allows float but with a little platform grip.
It's been a rainy couple of weeks, now this week it's going to be clear with wild diurnal temperature swings. Ice on the wooden bridge this morning, melting fast. Unusual!
The front wheels run right under the hands but the couple of puddles I encountered went slowly enough they didn't spray me.