The website is still up:
Ocean Ribs New Ribs Boats For Sale In The UK Ocean Ribs New Ribs Boats For Sale In The UK
Although I've not seen Malcolm around (he lives near me) for about a year, and haven't had cause to call them.
They moved a few years ago, slightly more inland, and were at the time producing more fish farm tanks than RIBs, if any at all.
Better contact details are on the Purewell fish farm equipment website:
Purewell Fish Farming Equipment Ltd – For all your fish farming needs!
I was always expecting to see the company up for sale as the brothers would no doubt be looking to retire, but may have missed that opportunity.