The Esterbrook J series double jewelled pens of the 1940s were made in three sizes, the 'J', 'LJ', and the shorter 'SJ', this pen. At 15.2cm. posted for use, however, it is still a good sized pen.
The pen is finished in classic Black, with stainless steel trim and twin black end jewels. It has a good surface, a deep shine, and a clear barrel imprint.
In great condition, a new ink sac has been fitted, as the old one had hardened with age, and the pen has been serviced and tested. The nib is a '3668', which Esterbrook lists as a 'firm medium for general writing'. The 3000 series nibs were known as 'Sunburst', no doubt referring to the gold plated finish. They are also the first nibs to have a hard material tipping, Esterbrook coined the term 'Osmirdium' for the alloy containing Osmium and Iridium. These nibs are much harder to find than the other series but are the best looking and technically more advanced
The nib is unused, it arrived in the original box as a replacement nib, presumably the owner wanted a 3668 but never fitted it to the pen. The gold plating is still intact on the ball of the nib where it touches the paper, it would have worn off very rapidly as the nib was used.
The stainless steel trim, thick celluloid, and excellent build quality make the Esterbrook SJ very practical and durable vintage pen.