[Barnmead]

Sinewave
Yes I did, although you can only see the front, the leather can is clearly has a 10S/ reference.

Perhaps Andy can say how this one fits in with all the others he has collated?

So far it looks as if 10A/ and 10S/ were going together for a while. Could it be that there was some minor difference in the specification or merely that some of those at the Air ministry that purchased new batches used different versions of the AP documents when placing the orders.