Other Leather Seal Question

I am about to undertake my first reseal job on a vintage Pioneer G6435 Chinese Air Pistol. I know the seals will be leather, but I do not know what size the seals may be. After I take it apart and take my measurements, is there a recommemded tool for punching out the various sizes I may need? I do not want to use scissors LOL.
 
well you have to form a leather seal first and then trim the cup
you will need a mold of the right size and a way to compress the leather in the mold, like a socket
the leather would have to be softened first
you just don't grab some leather and cut a circle
you might be surprised it might not have a leather seal and if the seal is alright, it might just need to be reoiled
don't know own one of those pistols
 
well you have to form a leather seal first and then trim the cup
you will need a mold of the right size and a way to compress the leather in the mold, like a socket
the leather would have to be softened first
you just don't grab some leather and cut a circle
you might be surprised it might not have a leather seal and if the seal is alright, it might just need to be reoiled
don't know own one of those pistols
I have never seen someone do all that for a breech seal. They look like plain jane leather washers to me.