I have been looking at old L322 4.2 sc's and two I am thinking about are as follows.
Both 07
Both have long mot's
Both same price
One seemingly has stacks of history and paperwork etc and just over 200000 miles
Other has no so much or hardly anything but just over 100000
Both are more or less in the same condition.

Me being me would go for the lower mileage despite no or hardly any history etc. Or go for the one with double the miles but lots of paperwork.

Opinions please..

I'd be looking for clues of care on the 100k one, like does it have 4 matching tyres ? Is there still a matching spare in the boot etc. Or has it been maintained on a shoestring with 4 unmatched cheapo tyres ?

On the 200k one, whilst it's got paperwork, have the jobs you'd want to see actually been done, or is it just an annual oil & filter change. So have the gearbox & diff oils been changed etc ? And also the same tyre test as above - that's normally the first thing I look for on any car.

I know what you mean but I am a few hundred miles away from both and unless they are willing to check and do all that for a sale, I have had it.

Oldgit, no harm in asking the sellers for all the history. If they are genuine sellers and know their stuff on these I'm sure they would be more than willing to send you them seeing as you are a serious buyer.
You could also put a shout out on here and ask if anyone local to the sellers could give them a once over for you.
One has done double mileage than the other and with lots of history but with such high mileage, everything that has been done to keep it in tip top condition, could need doing again around about now or soon after. I'm not a snob, but when I've bought my fatties, if the pictures of the car are taken outside council houses or estates, that puts me right off the car. I'm sure we've all bought a car at some point, only to find various components have either been cable tied, glued or gaffer taped together. As Alistair said, dodgy part worn tyres, or fitted with the cheapest tyres is a good sign of repairs budget. No doubt whatever car you choose to buy, there's a very good chance you'll need to spend a couple of K to get it back in tip top.

The seller for the lower mileage one is the "middle man" as he put it and getting hold of the seller was proving hard and getting more photos and details wasn't easy at all so decided against it.

The other one is still on but understand what you say about things still probably needing fixed etc.

The thing is, they are both 4.2 sc, now apart from the power difference is there any reason to get one as opposed to say the 4.4 non a i can get one closer.

Probably a wise choice against the lower mileage one if they are being vague with answering questions.
I think it's more down to personal choice, I've always wanted an sc just to say I've had one and to experience the power. But since I've had my 4.4 TDV8, there's more than enough power on tap. I was shocked at the speed it took off when i really boot it. Things can go wrong on both cars that can amount up to an eye watering bill along with maintenance. If it's a sc you really want, just keep looking and I'm sure the perfect one will come along. I suppose it doesn't help that you are far north and can't just take a 2 hour drive to view a car that's reasonably local.

As has been said it depends if it was looked after well.
Mine is on 260k same age 07 mine has had engine oil and filter every 6k gearbox and diffs every 30k front arms regularly all bushes air bags shocks etc some things need replacing because they are worn out some because of age so for me the mileage is less important that the way it has been looked after
I also believe these vehicles do not like sitting around mine is used every day and after all this time it shows no fault under diagnostics
Hope this helps