Selma definately did make Colt Rev. Rifle ammunition....I'm not desputing that fact. But, there is no evidence that they didn't simply use a standard Colt-made mould.
My "issues" begin when an unusual (mis-cast, or poorly cast, or cast in a worn-out mould, etc, etc.....) bullet is identified as something they probably are not. And that id usually has to be something rare and valuable.
Ian, there is a Selma Arsenal label/box (see "Percussion Ammunition Packets") but I do not believe there were any cartridges in the box.