Originally Posted by JohnDThompson

The original equipment was 590mm ERD rims. The Sun CR-18 is available in this size and in a variety of spoke drillings, e.g. 32, 36 and 40 are readily available. Otherwise, a 700C rim should fit through the frame, but you probably won't have clearance for mudguards.

Tektro makes a long-reach dual-pivot caliper that worked on my daughter's Sports with 26" (590mm) rims:



The older hubs should have the 120mm OLD you need, and should be quite usable. AW hubs are quite durable, even in the face of neglect; often simply flushing them out with a solvent and then oil is enough to get a faulty hub working again. And failing that, they're not hard to rebuild. There are also AWC hubs that combine the AW's 3-speed mechanism with a coaster brake. These don't suffer the reliability problems of e.g. the TWC hubs.

If you have the crank and bottom bracket already, it's probably more cost effective to change the gearing by replacing the rear cog on the hub. These are available from 13T up to 26T and don't cost much. You can fit a cotterless crank, but you'll need to use your present 1-3/8" x 26tpi cups and search for an appropriate spindle for whatever crank you select.