MOT advice for a 110 2.5D

Hi, I've been living in Spain with my 1986 ex military 110 2.5D for the last 16 years. It was changed to Spanish plates many years ago and has always passed its ITV test, but they don't do an emissions check on it.
Now I'm back in the UK and I'm thinking of putting it back on UK plates and keeping it, despite the fact its LHD.
I'm just wondering how easy it is to get these old engines through an MOT? I've never known it not emit some visable smoke and they're not exactly efficient. I'd rather not change to a tdi or other engine unless I really have to.
Thanks.

My 2.5na used to pass fine. On a vehicle that old it’s just a visual smoke test and a probe up the exhaust for a numerical figure, so I would take it to an old skool type village garage with time served mechanics that understand old engines etc rather than a National chain with spotty youths etc.

will be fine, and even if it fails on smoke you can adjust the fuel injec to on pump to decrease that, and do a few other things (injectors, pump rebuild etc).

if it was me I would run injector cleaner through it and a couple of tanks of premium diesel and just put it in for mot and see what happens, will likely be absolutely fine.

that of course is assuming that your engine is in a good state of tune and not super worn out etc

You will be fine.
https://assets.publishing.service.g...-standards-for-road-vehicles-19th-edition.pdf