One of the fundamental items that I believe change during this era is braking systems changed from single circuit to dual circuit. My Acmat caused a bit of stress as the parts manual stated it had a single circuit but to be imported into the UK in 1982 it had to meet the then current rules of having dual circuit brakes.
That would be a good start to find out which euro year brake standard they want you to refer to.
If I would of had to convert mine to dual it would have cost a bomb, but I am thinking you could get later model bits from breakers yards, pretty much bolt in. But as you said it would be nice to have what you need to do in a list upfront than guess.
I am no means a UK DVLA expert, I have to use an engineer in Australia to approve mine to the Australian Design Rules, which are stricter than euro blurbs