Nice bike Alekhine

I am going to be a bit more general and say
steel frame, rigid enough that it won't flex when fully loaded, long chainstays and slack angles. Good clearance so you can mount large tires and fenders. Braze-ons for racks.
Stem that is adjustable so you can fine tune handlebar height
A high gear of 100 and a low gear of 20
Phil Wood hubs and BB
Handlebar with multiple hand positions, shifters on the handlebar.
Leather saddle.