I finally found the B40GA entries in the ARN registers. They are in Ledger 16 pages 159 - 173 (ARNs 94785 - 95234). This makes a total of 449 bikes, which would be correct as according to the bsawdb40 site, one was kept back as a development bike for the B40GB and still exists. It should be possible to work out which state each bike was in from the disposal unit so once I have that worked out I will update this post. Most of them appear to have been disposed of from 1971 - 73, with a few later. The ledger also shows engine number changes made. Interestingly, entries from 1942 are only two pages before and page 158 is very interesting as it shows the bikes the Army was trialling up to about 1962, including several B40s and a couple of C15Ts, amongst other makes. Whilst ploughing through the several thousand pages of these registers I have also come across and made a note of the WM20 entries and will make a separate post on where these can be found.

1966 Triumph Thunderville
1970 TR6C