NOS is great if you can find it, but used isn't terrible, most of the time. Many of these Shimano hubs are pretty tough if not completely abused by their former owners. I still have a 7-speed HG freehub that I was given years ago as part of a $10 deal with a bike frame left outside in the trash yard behind the LBS for 10 years before I got it. New ball bearings and occasional use of a Freehub Buddy still keep it in great condition. What you're looking for is something like a Shimano 105 FH-1055, HG/UG 36-hole 7-speed.

Is this for one of your Fujis? I can report I recently installed a modern FH-5501 130mm 36-hole Shimano 105 8/9 speed hub with 7-speed 14-30 cassette (made out of two HG cassettes) onto my Fuji Berkeley (formerly 5-speed freewheel with 126mm stays). By removing the large spacer for a thinner one, and carefully adjusting the axle spacing, this hub needed only a very slight tug to pull the wheel over its beveled washers and into the dropouts. No trimming of the axle was needed, as the Suntour rear derailleur hangar allowed a longer axle without protrusion.