First off

to the forum
I agree with Russ about your stamp being quite faded and toned. The peroxide might help with the toning but nothing can be done with the color.
I do believe that yours is Sc#65, and most likely there is no way to determine if it was another issue so it would be a safe one to try out the technique.
Best of luck, and if you do the peroxide clean please keep us posted how it comes out.
Ron
Side note to Russ: Has the Western cattle arrived yet?