Had contact with my colour-deficient friend today. He took the CAD test three more times at Gatwick. The main difference being that the CAA use an old CRT monitor for the test, while City use a state-of-the-art LED flat screen.
Despite this, he still managed to pass - albeit with a slightly worse score, but still with a good enough average to record a pass. Just the rest of the Class 1 medical to go now.
Incidentally, he was told that he could have had the three extra tests done at City University in the same session as the 'marginal' pass, and saved himself having to pay a further £150 for retesting at Gatwick. Worthwhile knowledge for anyone who scores a marginal pass at City.
Should I decide to go for a Class 1 myself, I know my old lantern test result will not be enough for an initial Class 1, but would probably use the same method of doing the City test independent of the CAA. I know my friend felt more confident doing the test at Gatwick with the knowledge that he knew the extent of his colour deficiency; he had experience of taking the test, and that he knew he had the ability to pass it!