Been onto Bovington to see if the have a plan pack and factory blue print drawings of the A13 Cruiser Mk 3 tank but no luck so far either slow or closed for a while. Anyone know who else would have the sizes.
I think this might be the wrong forum for a WW2 tank. You might get more traction on Missing Lynx.
BTW, A13 MkIII was the Covenanter. Was that the tank you meant? That was designed by the railway company LMS and built by them, English Electric and Leyland. Perhaps these former companies have archives somewhere? If you mean Cruiser Tank Mk III then that is the A13 Mks I and II, which were products of Nuffield Mechanisation and Aero. Perhaps there is an archive for them too? I know that a lot of Vickers material ended up in the Newcastle city archives. Perhaps the same might be true for the others in their local city/county archives.
Early Dec was a very busy time for Bovington as the entire WW2 Hall was being reorganised. I would ask them again. In general, Bovington only has "proper" drawings of in-house designs. There are exceptions. There would be little need for WO, WD or later MOD to hold production-type drawings. That would be - and still is - the responsibility of the design parent company.