The bloke who put the sh1t up you lives in Holland - so he's well qualified to discuss CAA nonsense!
Come on, give me a break. First of all, I have a CAA-issued PPL, this is all JAA stuff which applies in the Netherlands too, and I did search the ANO and LASORS. So that fact that you and me are separated by 100 miles of water or so isn't entirely relevant.
But furthermore, UA posted a question based on another comment I wrote, and that question thus seemed to be directed at me. I answered to the best of my ability and once the question started to exceed my ability, I became very cautious. "I don't know", "you may well be", "couldn't find", "I suspect"... I have never stated as fact that he was flying illegally.
If, for every question that's being asked on here, everybody just sits on their hands until the true, know-it-all expert comes along and gives the definitive answer, it would be a dull place indeed. And I can point you to numerous examples where it took a couple of experts discussing together to arrive at the final answer, sometimes prompted by further probing from non-experts.
Which brings in my next question: Can you show the regulations where those grandfather rights are introduced? There may be stipulations in there which the OP has to abide by. I can imagine that those grandfather rights are only given when you can show logbook evidence of having been trained on taildraggers.