Wanted for a mid-70's British "club racer" build. Let me know if I am missing anything!

-SA 3 or 4 speed hub (first choice is 4-speed). Laced to an alloy wheel would be a plus, as would it being set up for 125 mm spacing. Dyno hub ok.
-Front dyno hub in working order. Laced to an alloy wheel is a plus.
-25.0 mm seat post (non-butted 531 frame)
-Leather saddle
-Appropriate single ring crankset to use with the SA Hub. 167mm bottom bracket shell.
-Source for white fenders

Also, the brakes on my 20" wheeled Chiorda folding bike are broken/flimsy. I'd be interested in some Raleigh 20 brake calipers if anyone has them. They should fit mine probably, yes?

All parts will be well loved, I promise! Let me know what you have, and I'll see if it fits my budget