WD16H engine and frame numbers

Looking at the various lists available, it seems that there are gaps in the numbers known versus the numbers expected. One way to try to fill these gaps is by making an inventory of all existing numbers. This wil inevitably be an incomplete inventory (many bikes lost, not everybody responding etc) , but it will hopefully give some insight in the numbers. 

The W numbers are the original WD16H War Department numbers from late October 1939 onwards. Prewar military bikes had numbers without the prefix in line with civil bikes. Civil M/C's did not have matching numbers.  
Initially, spare frames and engines were numbered in line with the ordered M/C's. On later contracts it is not clear if the spare Frame numbers were consequetive with the contract M/C's. Frequently found are engines with an AS prefix.  These are Army Spare engines. The number of frames (and sometimes engines) found without the W may however be an indication that the correct numbering of spare/replacement frames  might not have been so rigorously followed. It may also indicate to a number of parts made but never used for any bikes, dumped on the market after the war.  

Dating the bikes based on the contract numbers is a tricky issue. Bikes made on a contract date in one year could very well have been delivered the next year. I added the most likely manufacturing year without pretending to know it exactly!

I also have found different casting numbers on head stock and saddle fixture. If anyone has these numbers, please add them.  Frame number is found on the left hand front petrol tank frame lug casting. Engine number is found on the left top corner of the left crankcase half, see pictures below. Found on many engines is what is believed to be a Quality control stamp comsisting of a broad arrow over an M and with a number underneath. On all engines, bore and stroke are given at the right hand upper corner.

Frame casting numbers are found at the left, aft side on the steering head, saddle casting number is found on the left-hand side below the saddle. 
Petrol tanks have individual numbers at the bottom, front forks have individual numbers at front lower cross brace.

Finally, adding the gearbox casting and serial number might give some info as well. I will add numbers to additional lists if it is useful.  

If you want to help unravel the past, please send me your frame and engine numbers (and preferably the others as well).
If you want to have your bike on the website, send a picture.

Rob