I first called on Mark with a car I'd just bought, the seller saying "It just needs a re-gas". Mark correctly diagnosed that even though a re-gas would get it "sort of" working, the compressor looked to be on the way out. Indeed it "sort of" worked, so we removed the gas and I fitted a secondhand compressor. It had lost a little gas, so he advised me to search around with an ultraviolet torch for a small leak. I found a small leak, repaired it, and Mark re-gassed it. All in all, he probably charged me about 50% of what he should have, explained gauges and meters, what they showed and what it all meant. Patient, and tenacious, he wasn't going to let this beat him. The car is now supercool and I cannot recommend Mark enough.