Here is the build I’m considering. I like James Black’s bikes and want a similar take but with the addition of three speeds.
I’ll be riding it around town and for light weekend trips.
Please weigh in if anything jumps out as problematic, or a missed opportunity.

Comes with frame:
Shimano cartridge BB
Aluminum seatpost
Aluminum steerer tube

To buy (through Peter if he can source it):
Sugino single crankset 170 mm
Sugino chain ring 42t
Shimano Nexus 3-speed hub
Sturmey Archer SLS30 index thumb shifter
Sun CR-18 36 hole rims, satin
DT stainless spokes
Deore front hub, silver
Sugino cantilever brakes, silver
Sugino mountain brake levers, black/silver
Aheadset, silver
Black cable housing
Panaracer HP406 20 x1.75 black/gum tires
MKS AR2 quick release pedals, black

Parts I have and might recycle:
Raleigh "North Road" or GB Maes bars both 25.4
(drops would require road levers)
GB 110mm or Nitto Technomic 130mm stem
Avocet touring saddle