Got an email from Eric Kovacic of EFW Arms. Sound like his company will soon be making some of the long barrels and shrouds soon, I only asked him about for the Dan Wesson 15-2 .357 Mags, though.
Thanks for getting in touch, and sorry for the delay in getting back with you! Currently I am coming out with the longer shrouds. I am shooting to have available some 15" barrel assemblies in about a month. I got you down on the list to let you know when available. Thanks again!
E.W. Kovachic Technologies
210 South Park Street
Richmond, OH 43944
He does have the 10", 12", and 15" barrels in stock right now, just no shrouds. So if you have the shrouds, but a damaged or missing barrel, you can get one.