I have used them recently Ted for my NC30. I also used them a few years ago to remove a big, creased dent from my polished alloy Triton tank, absolutely perfect.
They did a great job electroplating the NC30 tank but yes, expensive. However, considering every NC30 tank on eBay was full of rust just like mine or badly dented and a new tank from CMSNL was over £1500 and unobtainable anyway I wasn't left with much choice. No way was I going to use a tank liner I absolutely detest them, nothing but problems from preparing the rank to a few years down the line when it starts to peel!
Andy from MCDR kept me informed and sent photos during every stage of the work from initial cleaning, pressure testing prior to plating and pressure testing following plating. He also sent two discs of steel when he returned the tank to prove the thickness of the plating.
If you check out my NC30 thread on here you'll see the quality of his work.
Would I recommend him, absolutely and especially a lot of carb issues on our old clunkers are a result of rusty fuel tanks or failing tank liners.