From the cited reference, the FIRST line reads: "The Smith & Wesson Model 10 has been in production since 1899 when it was introduced as the Smith & Wesson .38 Hand Ejector Model of 1899."
A quick check of most any reference book will show Smith & Wesson began identifying various handguns by model number in 1957. Prior to that, they were identified by a name, in this instance the 38 Hand Ejector.
I will agree the reference statement is vague enough, but the vagueness is misleading. I will also agree the revolver was essential the same except for some manufacturing changes (better metallurgy, an improved hammer/firing pin block - which happened long prior to model numbers, the shape and size of the front sight, and eventual ceasing to use external screws. No item marked Mod 10 existed prior to the change, initiated in 1957 and subsequently.