It would seem upon further checking that the TD number
is the WD number though why the D was added is a mystery. The WD number range for T-16 was T92001 to T107000. As the D only seems to appear on the earlier listings, it may well have been a mistake?
My earlier position was based on the fact that in US production, the Ordnance number is not the same as the USA registration number.
You never stop learning!
