I spotted a sailor knife at a local market. Judging by indirect signs, it was made before 1870s due to its integral steel bolsters. I decided to compare it to a known example with a clear stamp (the stamp on this one is almost completely worn off, leaving the Sheffield inscription). Some things show that this is it, but Im still not sure. Maybe someone could give me some advice?

Anyway, lets show photos of our knives I came across this example recently, the stamp is hard to read, but its J J Saville. They began their work in Sheffield in 1876. Quite a cool company, they made excellent knives for cutting German mine cables during WWI. This is a full flush joint - in the half stop and closed position the tang it matches the shape of the bolster, unless of course Im mistaken with the name of this type of tang. There no England stamp, meaning its presumably older than 1890

My gosh you have an immense knowledge of old Sheffield knives. Thank you for sharing your knowledge.

Oh no, I dont know anything at all, I just read AAPK, there are real monsters on this topic there, and all these cool guys and organizations who wrote this article, other articles and a bunch of books