Serven's Colt book gives some information about them, and as is typical of Serven, not a great amount of detail is provided. He does say that there are both military and civilian versions of the 1905, and also that the civilian version was available nickel plated. He also says they were chambered in both .38 LC and .38 Special. I am not sure exactly what that means, as I don't know if all of them were chambered in .38 Special so the .38 LC could also be used, or whether some were chambered in .38 LC only and others (civilian?) in .38 Special.