The older Ithacas and other shotguns of that era were not designed for modern shotshell pressures. I have two Ithacas (newer than yours by twenty years) and a Parker made in 1905. I shoot only low pressure shells that I load myself - pressures less than 7K psi.
I also shoot BP shotshells in one of the Ithacas. Those I load also.
BP shells would be kinder to you gun. Republic Metallic sells new paper hulled BP shells - the kind that gun was made to shoot.
BTW and FYI - "low brass" is not an indicator of power. Remington "heavy" dove loads are low brass; Federal's small game and dove load is a 3 1/4 dram Eq. and is low brass.

Pete