I got an extra brand new Mullins Chain Drive hub for sale. Still in the packaging. Email me if your interested. email@example.com. Here are the specs from Mullins Chain Drive website on the hub. Just the hub no axel. $275 plus shipping.
-The Richmond Spool is CNC’d from 6061 aluminium
-Hub includes crush sleeve and 2 sealed cartridge bearings for 3/4” axle
-Hub includes 2 star hub tins and hardware
-For use with 40 spoke rim
-Over all width 3 11/16”
-Available in polished finish