Hofbchsenmacher is just a marketing title and warranted a yearly fee to a court, most of the time just a figure-head court, where he had previously submitted examples in order to be dubbed the title. Bonn was where he hailed from. Is it a 20 or 16 bore. Equate the service pressure at the time with a current 65mm cartridge and it should be fine but you may want to have it inspected by someone who knows and may save your fingers.

Kind Regards,

Raimey
rse