Two other things to consider if you’re buying one of the hubs from the shop:

1) How many spoke holes do they have? While it seems as thought the majority of 3 speeds sold in the U.S. came with 36 spoke wheels, 40 spoke S-A hubs do turn up here. The other possibility from the mid-60’s on is 28 spokes which were used on Sting-Rays. If they are AW’s they all have the same gearing but this could be a factor in finding a rim. You didn’t say what you’re planning to use for a rim, but you’ll find the choices for 40 hole rims to be more limited.

2) Do either of the ‘50’s hubs have an Alloy shell? If so, the word Alloy will be stamped on it. The 4oz weight reduction isn’t a big performance factor on a 2 + pound hub, but there does seem to be a segment of vintage bike fans that keep an eye out for these and therefore they have more value than hubs with the standard steel shell. Many of the Alloy shell hubs that I’ve seen (including 2 that I own) were dated 1953.

Good luck with your project.

Regards,
Alan