well i was going to say, Sykes Pickavant Diesel Engine Compression Tester, but looking at
affordable, the used ones on ebay (£40 - £70) these seem to be old school and there is a lack of
LONG extensions that you need for a modern direct injection diesel engine, where there is a deep hole passing through the rocker , the ladder and the head.
found one that is
MAYBE suitable, so must have been made in the last 15 years... has extensions .. but are they long enough?
https://www.ebay.co.uk/itm/257031041108?
so beware of the testers with only short extensions
sykes do them new and with long extensions.. but at a at nearly £400 are out of reach - and they comer with no storage case?
seat cutters .. don't know anything about them, but have seen the company "Laser" branded about by pro mechs
and talking Laser, back to compression testers .. this looks good .. perhaps use 4510 and look for cheaper listing
https://www.ebay.co.uk/itm/178060705225?
note these kits use "o-rings" important they are in good condition on a used one .
all the best.mark