Phatman; Two choices that may possibly have merit for you:
1. A SunTour 5-cog Freewheel is an extremely common vintage part, not a problem in find in “Thrift Shops” my favorite vintage parts supply source. (You’ll need a Park FR-2, or possibly an FR-3 tool to swap). Best news is at a Thrift Shop you’ll get the complete bicycle (hubs, rims and all) for as low as ten to twenty dollars!
2. Since you're located in Columbia, MD you're quite fortunate to have access to Mt. Airy Bicycles, a pleasant cycling ride through Howard County to your West. The owner, Larry Black is one of the greatest bicycle advocates to grace the Washington Metro area. He has enough vintage parts on hand to equip nearly anything you could drag into his shop!
Meeting Larry is worth your time and effort to travel west the dozen or so miles to get there. Mr. Black just a month ago completed a metric century on a turn of the century "High Wheeler" no less! So even if you have 2000mm rims he may have just the hub you need....
Need directions? Not a problem, here’s the URL to Larry’s shop
http://www.bike123.com/
Cheers; and God Bless…