Richard I think you are correct, the cut of the sporran with the slight point at the bottom reminds me of some of the older late Victorian / early Edwardian era doublets that had tashes that were a similar shape. The closure is different as well.
I’m sure in your collection of old catalogues you’ll find something similar that may narrow down a date.
Being male is a matter of birth,
Being a man is a matter of maturity,
Being a gentleman is a matter of choice!