I made incredible progress on the DKW seat. I kept putting off the "shaping" of the aluminum, since it can be a huge pain in the arse to cut. Cutting wheels get gummed up, this 1/16" material is a bit too thick for my small shears etc. After applying some masking tape to mark the cut lines, I discovered the thin abrasive cutting wheel on my angle grinder cut through it like butter. No gumming up, no galling, no crazy super hot burr. The masking tape must provide some sort of lubrication in this process, because it was a million times easier cutting it with the tape, versus when I cut it without the tape Saturday. Lesson learned!
After that, I wet sanded it with 1000 grit and WD40, then 1500grit, then 000 steel wool. Then I installed my new 6" buffing wheel on my angle grinder, and dug out the white rouge I had sitting in my file drawer for the last 15 years. I've never really polished aluminum before, as I really like the look of the 000 steel wool left on previous projects. So I wasn't sure what to expect with the buffing wheel and rouge.
What I got was an instant and very easy polish job. Like maybe 5 minutes total was spent on the wheel, with light pressure. I topped it off with some Meguires AL polish on a terry cloth towel. The polish is great, and matches the tank well. You can still see some of the marks left from the extruding process, so I could always do some more sanding and a re-polish if I feel like it.
I gave the seat a bit of a coke bottle shape. Thinner at the front, wider in the middle, then tapers a bit at the back and has a cutout for the under seat mounted exhaust. The three screw holes at the back will be used for mounting the taillight assembly, which I haven't even fabbed up.
Last bit of good news: The stock length kickstand appears to work perfect at the ride height I intend to run the bike at. And the new custom springs I sourced seem to be just right. Some cafe style bikes have low and hard suspension, which looks great. But all of our immediate streets have such shitty bumps and potholes, I've discovered softer it better for normal riding. So I took a bit of a gamble on some springs from McMasterCarr, and I think it has paid off.