Lets clean up the photo first.
Patent dates moved from top rib of barrel at start of 1899 production
Use a good screw driver (CAREFULLY!) to remove the left side grip panel.
Here is where you will begin. There will be a letter code stamped on the frame. For the small frame .32 s&w 5-shot the dates are; A (1909-1915);G(1915-1926)and J(1927-1940).
A = 1897; E = 1898; F = 1899. The easy way to remember: If it has an 'F' it FLUNKS the Antique Test.
There is some data for the small and large frame revolvers available in the following serial numbering system:
Small frame= 1911(A30201-A66700); 1919(G31001-G39500); 1920(G39501-G46300).
I'm emailing you some other info.