Does this shape appear in other series? No, not in other series, but a similar shape does reappear towards the end of the Early Series numbered Early Series 460.
There was formerly some confusion about the shape number, brought about by one of the first-recorded pieces being mistakenly numbered 106/7 instead of 107/6. More examples have now been found however, confirming the shape number as 107.
Two sizes are recorded.
Painted number 107-8-B. An unusual form of number, painted not incised.