Think I read on Wikipedia or somewhere like that that teh ex-MOD ones are (or should be) all normally aspirated. Apparently the army like to install 24volt generators on them, and the turbo engined ones weren't suitable for some reason.
The MOD spec 90/110's delivered the 1980's & early 1990's were all 2.5NA D apart from those used for a specific purpose in which case it would have been a V8. The TD & 200TDi were never used in the main fleet and it was only with the introduction of the 300TDi in the Defender XD (Wolf) that a more modern engine finaly made it into the widespread use.
The 300TDi was made under license in Brazil towards the end of its life and that is where the engines were produced up to only a few years ago. This engine (minus the EGR set-up) was offered in MOD & ROTW spec vehicles and of course for those wanting a LR genuine parts engine for upgrade or replacement.