Thank you for posting the picture. If the frame mounted firing pin hammers are shorter than the ones with the hammer nose, that may make a better "bobbed" solution.
I have a model 65 with a factory bobbed hammer and it is shaved much more, very smooth and has little if any ability to snag. That is what i am hoping to achieve.
You'll be able to do that. In fact bobbed hammers are not that hard to find online.
Just make sure that the base of the hammer junction to the top of the main spring strut bar are compatible. Early ones have a ball and later a forked junction. Although struts are cheap and easy to find and change to match a hammer you buy.
if you lighten a j frame hammer to much it may not work .you can lighten a larger k/n hammer with out issue. that is why a bodyguard hammer has that extra lump of metal added
Why not just buy an extra 3541 or 637 hammer, bob it then put the original hammer off your 351PD in your parts supply in case you ever need to switch back.. The 638 hammer is ugly when used on an exposed hammer model.