The website unimog.co.uk is owned by that high Bentham garage. UK distributor of parts and main dealership. Specialising in conversions. I think if you wanted to buy a Unimog in the UK and needed a specialist conversion Mercedes-Benz will just send you to this company.
As an aside, I applied for an academic scheme at Lancaster University where you work on an industry / University project, get a research masters and hopefully end up employed in R&D at the sponsor company. Can you guess what the company was? Atkinson Voz at High Bentham! Yes, that unimog garage! I didn't actually apply because the academic advisor for that project was a beep beep and told me not to bother applying. Shame really because my interview would have been about the possibility of driving a company car! Not full time just to give it a go one time. I reckon they have somewhere to test them.
Atkinson Voz is a small but very knowledgeable team of unimog experts. If you get one from them you will be getting a good one. Real good engineers at that place.
Atkinson Voz Ltd, Wennington Mill, Bentham.
Now why don't you visit their site and drool over the available unimogs. I did!