W&S. Blue velvet could be attractive to show off the gun, however an original factory casing for a .38SA would not have been with blue velvet. The only original casings, I know of, are lined with Chamois skin, a very light beige/cream colored felt type material. See page 15 in the 1905/6 S&W factory catalog or see page 113, "Smith & Wesson 1857-1945," revised edit.. by Neal & Jinks, for a picture. The factory casings usually included a pair of interchangable target stocks, a hollow brass handle screw driver with 4 blades, and one interchangable single shot barrel, and one brush wiper. Having said that. there are after market cased .38 SA models done by the various New York City S&W distributors, that have blue satin material used to line the cases. Bottom line: It's your call as to whether you want to match the look of original casings, or a nice casing that shows off the gun. At the time .38 SAs were being produced, all the S&W logos you see in ads for their guns at that periods are in black & white. Blue, or other colors, were not colors associated with the logo then. Ed.
