To John (Jol), I have been re-examining your photo of the engraved signature (enlarged while twiddling with colours, gamma and contrast). The design number prefix of a B (for Blomvas) tends to be engraved like a 13.
I do not think that they used an oblique stroke to separate the design number from the second engraver number.
Possibly the design number could be interpreted as B1719, which would probably place it into later production around 1970. Engraving done very quickly onto a small area can be almost impossible to decode.
My prized very large StrÃ¶mbergshyttan vase was advertised with a strange maker's name because the seller read the engraved name upside down, but I recognised the shape and got a bargain!
To Pip, the unrepentant Pedant. I do read the complete thread before responding. I was attempting to assist John (Jol) to correctly read the complete engraved name on his vase, which was the original purpose of his thread.
Some of these were engraved "StrÃ¶mberg" but this one has the more common "StrÃ¶mbergshyttan" engraving, but the final letters tend to dissolve into gibberish! My expertise is limited to my own collection, with some help from Leslie Pina, and those that contribute to this and other web sites.