I filed an I.H. Sorby backsaw for an acquaintance. In itself that went well. Only some of the teeth were already broken off. I have now filed them. The steel (Cast steel) is quite soft, so another tooth also broke off. This does not affect the sawing itself. The saw has 12 TPI. This brand is an unknown brand in the Netherlands (we know mostly Slack Sellar and Spear & Jackson here). So I started searching here, but I still can't figure it out. The history of I.H. Sorby is quite complex, especially for someone whose standard language is not English. I have attached pictures. Furthermore, I can't find anything about an etching on the sheet. Who can give me more information about the age of this backsaw? Thanks in advance.
Wim - Hi - the complex history of the Sorby family is untangled here . . . . Simon Barley suggests a date of c1870 for a stamp similar to yours.