W126 - Euro vs North America

[Oliverp]

Hello
I haven't posted here for quite some time. I haven't owned a Mercedes for a number of years, and I have moved from the UK to Canada (Toronto).
I would like to own a W126 again.
I know the cosmetic differences between Euro 126's and North American 126's, but I'm not sure about mechanical differences.
I know the v8's had modifications (CAT?) for emissions reasons, but how about the straight 6 300SE/SEL?
I had an idea of importing a left hand drive w126 from the UK. They are cheaper because they are less desirable (right hand drive is the norm in the UK) and will already have the euro cosmetics, but how much mechanical work would need to be done (without taking into account the condition of the vehicle)?
I've found various articles but I can't seem to find anything 100% exact, or confirmed.
I'm hoping I can open a thread here and maybe find someone with experience.
Thanks!
Oliver