Well done you clever people, my mystery purchase was a braiding needle for making fishing nets. The lovely stallholder at the antique fair told me how she used to earn 6d pocket money by threading them up with sisal ready for her mother to make nets in Grimsby. Everyone would mark their needles with their name or initials so that they kept their own. The father of the stallholder (I should have asked her name) used to make the needles, and the cut out at the pointy end became clothes pegs - no waste in those days. These days nets are made by machine but I have found a few images and websites for more information and, if you are in the area, the Grimsby Fishing Heritage Centre has a display of netmaking.
I also found the words of a song about the girls who made the nets, it's called Braid Away Dolly and was written by Pete Addison.
Now it's up in the morn to the braidin' I'll go
To the cold salt and tannin down old Fish
Where the work it is hard and the pay's not so hot
It's thirty-nine shillings, is all that you've got?
With your needles a-clicking, a-swaying and rockin'
Braid away Dolly, as firmly you're lockin'
Braid away Dolly and sing us this song
As the miles of manila are twined into one.
Now you've got to be fast and your stitches all tight
'Cause Laura she's watchin' to make sure it's right
There's Joe Littles and Shooters and Bellytops too
And Wings that are creasin' way out of view.
Now it's fill up your needles and make 'em a double
It's cod ends we're stitchin' and they're naught but trouble
Fill up your needles, it's six pence a ball
And Elsie's a-callin', she's fastest of all.
Well we've stitched you a net and we've braided it right
And it's ready for trawlin' beyond the Spurn Light
It's out on the Dogger and the cruel North Sea
A-catchin' the fish that you bring home to me.