I worked on some brackets and was waiting for my drill to recharge when an idea hit me. On my previous build that never had a frame, 4-4-2, I was working with two chain wheels to add more gears with a SA 2 speed kickback hub.
I thought the cottered cranks had no way of doing that but looking at my sprockets I see how it can be done. I have a 40 tooth and a 44 tooth cottered crankset. The chain wheels are slightly concave so I can cut the smaller one out (they are one piece with the crank arm) where I drew the blue lines. Then drill 5 holes to match the larger one and bolt them together, flipping the smaller one to the outside. It looks like enough spacing for the chain, but washers could be easily added to make some space.
With the SRAM automatix, that makes 4 speeds, but how to shift between the two chain wheels? I had made plans for long dropouts to take up the chain slack and align the rear wheel every time I changed the front gearing, on 4-4-2. This hub is freewheel though, so there's no coaster brake to have to contend with. But I don't want to have a cable and shifter and derailler to deal with. I'll keep it simple and shift manually up front.
I saw a pic of a floating sprocket and that gave me yet another idea. Between the two chain wheels, 44 and 40 teeth, could a floating chain wheel take up the slack when dropping down to the smaller chain wheel? I have a bunch of candidiates for a floater, from 36 to 52 teeth. I think a floater shouldn't need to have the wheel loosened to pop it in. But I've never used one yet.