Very nice Alan
It would be worth looking at this resource, with links to more
https://www.shotgunworld.com/threads...-shoot.366087/
c. 1894 1 1/8 oz. 3 Drams BULK Smokeless pressures were 6000 - 8000 psi; Dense Smokeless very similar to today's loads.
https://docs.google.com/document/d/1...aAfUOZEFU/edit
It would be reasonable to restrict your shells to 1 oz. at 1200 fps target loads.