As requested, curious to hear your comments Chapmen.

Matabele, Heinrich Scherping was fond of the tang mounted diopter sights recessed into the tang as many of his guns were fitted with them in various design. I have been collecting guns from his shop for many years & almost all his double rifles & drillings are fitted with them. If you search Scherping and stretch the search out to about 10 years I think you'll find pic's of others that have been posted here on the site over the years.

m4220