Rupert, I don't have access to any B Series ledgers, but if the entries for those September '39 models show "War Office" then I'd say there is a good chance.
Does the "Engine" book survive? They usually show "Tank Finish". The "Frame" books don't carry as much detail.
Hi Rik, yes the engine books survive.
At a glance I count the following went to the War Office during September 1939 these all being 1939 season machines built before the annual end of season shutdown in August -
KB23 x 5
KB24 x 26
KB26 x 10
Generally the build spec. columns for these machines are ditto the preceding bikes with standard civvy features I.e foot change, single downswept pipe, solo and chrome plated tank. No references to khaki/war finish or anything other than civvy spec bikes.
Interestingly no KB21 machines were sent to the War Office, despite a handful being despatched to the usual destinations through September and October '39.
The instruction may therefore have been "we need bikes, but we don't want any old rubbish, 350cc minimum".
Rupert, I'd have to stop and think where to find the evidence, but I've seen that the private owner purchase scheme specified a certain number of makers and 350cc OHV or 500cc SV. It was publicised thus in the motorcycle press...The criteria for bulk purchases from factories seem to have reflected pre-war contracts though. The War Office had bought 250cc "Training" motorcycles from BSA and Royal Enfield during 1939.
Hi Rik, no sign of any C/S Mark by any of the War Office KB's. What would that indicate?
From the dates of despatch to the War Office it looks like the man from the ministry came knocking on BSA's door during the annual shut-down as a small number of bikes went from 26/8/39.
Then when the workforce returned they got to grips with the job and most requisitioned machines went on or around 4/9. A few still remained, being despatched up to 4/10/39.
My assumption based on the 1939 specs is that "C/S" indicates "Chrome / Silver" so standard civvy spec.
Purchases in August suggest that they were planned. Germany didn't march into Poland until 1st September.
Hi Rik, sorry, my mistake, "CS" is specified for all the KB bikes sent to the war office, the style of handwriting makes it look more like CP, which I was taking to indicate Chrome Plate.
just as an aside, around 80 KB machines were sent to Warsaw earlier in 1939, no doubt the Germans found them quite useful.