I have a revolver seemingly identical to that, save for mine was blued and that seems to be nickel plated.
I had mine "papered" by S&W, which included sending in a description, with serial #, and a photograph.
The response indicated mine was a "model 1½." The paper says it's also refered to as the model 1½ second issue."
I am unfamiliar with the model 2, so I don't wish to make any absolute statements, but it seems to me that gun is also a model 1½. BTW mine is also in 32 rimfire.
Until someone more familiar with S&W revolvers responds and explains the difference I am going to maintain that gun is the same model as mine. If nothing else it ought to add a tad bit of spice to the thread.