Hi Simon
I've now heard back from my vehicle expert - in his opinion the motorcycles are either 1913 or 1914 models (some of each). In our research we've already established that there was a mixture of motorcycles in use, some of which were supplied by the owner.
I'm going to the National Archives at Kew in a few weeks and I'm excited to discover that the Indian Army Corps signals War Diary from September 1914 to October 1915 is available. That means, if it is complete, I will be able to identify all the French towns which the unit passed through, and thus I hope I will be able to determine exactly when and where the photograph was taken.
I've looked again what you said about the ASC photograph - I think I got confused, and realise that this is not the same men as the motorcycles picture.
I've also looked again in the medals cards but I'm afraid I drew a blank. It's the penalty of sharing a name. (Meanwhile I've also been researching the one and only Thomas Brabazon Lambert Disney - not too many of those!)
regards
Nick
