Air Ministry Military Lenses

Hi,

I've got a few lenses that I presume are WWII vintage, some might even be earlier. Many have an Air Ministry serial number on them (often painted on with a brush and white paint). Someone on an earlier thread identified a manufacturer from this number. Is there a list, anywhere, of how to decode these numbers? I'm curious as to who made some of the lenses I have and when.

Thanks,

Steve, my Ross 151mm f16 WA with AM stamp is WWI not WWII and is a Zeiss Protar design.

One problem with the AM lenses is that the same design was often sub-contracted, there were a number of lens manufacturers in the UK in the WWI-WWII era. So an AM lens might have been made by Ross, Dalmeyer, Aldis, TTH (Cooke) or one of the smaller companies.

The British government took over the Carl Zeiss factory in Mill Hill at the outset of WWI, this had begun as a Binocular factory but was also making lenses, this was placed under the control of Ross, so this may be why that compnay seemed to have most of the AM contracts.

Ian