I think your revolver has the older style frame mounted firing pin that was only used for rimfire revolvers. I believe that to remove those firing pins you need to remove the retaining pin and then press the firing pin forward. Then the firing pin and bushing will move forward into the cylinder window. This method is very different from removing the firing pin on modern MIM revolvers. I will admit that I have never done this work on an older revolver, but my understanding is that some caution is required.
This issue is discussed briefly in this thread:
Model 17 Question - Firing Pin