My six is a Service Six but they're similar enough that the same holsters should work for each type. I have a vintage Jackass shoulder rig (Jackass is what Galco used to be named until 1980 or 81). It is supposed to be for a Colt Detective Special. But to find another one like that would mean you'd have to search around a lot for one.
I also bought an out of production Bianchi rig that is labeled for S&W Medium Framed revolvers, but I only use the harness part of it (with another gun and holster) and have put the holster in my holster drawer. It is a simple holster made out of a suede. Here is a link to Midway that used to carry them so you can get an idea of what I'm writing about.
http://www.midwayusa.com/product/429543/bianchi-215-hawk-shoulder-holster-and-harness-right-hand-s-and-w-j-frame-2-3-barrel-with-hammer-suede-tan
Most K frame holsters should probably fit your six just fine.
As for the Barsony, don't waste a penny on one. Barsony makes junk, and though it's easier to get away with a cheaper IWB or OWB holster, you can't go cheap on a shoulder rig. Cheap ones like Barsony and any nylon holster will not distribute the weight well and will be very uncomfortable. You don't have to get some custom rig, but at least spend enough money on something from Galco, Bianchi or Desantis.
I prefer pocket carry and shoulder holsters for carrying anything bigger than a pocket gun. The last few months I have bought several brands/varieties of shoulder rigs/components and have found that sometimes it is best to get various components from different manufacturers and assemble your own personal fitted Frankenrig. My SP101 can ride in a Bianchi holster with a Bianchi speed loader pouches all attached to a Galco harness. My Alaskan rides in a Galco holster attached to a Bianchi harness.
Good luck searching for a shoulder rig for your out of production gun. It can be an extra hassle. But just make sure you buy quality because I can almost guarantee it, that if you go cheap and get something like a Barsony rig, or Cebeci you will be disappointed. If you search and search and search and can't find what you're looking for, shoot me a PM and I may consider parting with the unused suede Bianchi holster. Finding the harness would still be up to you though.
