I have a funny feeling that at time it was rumoured that Bruce had in fact bought the format to the show himself and taken it to ITV, rather than the other way round. But it was just a rumour.
Well, he didn't buy the format but his daughter did see the show on Dutch TV and suggested it to Brucie as a good format for him, and he then suggested it to LWT. As mentioned, he did the first three series and he said he enjoyed it, but he thought there was a bit too much straight presenting involved and not enough opportunities to muck about, so it perhaps wasn't the kind of thing he'd stick with for ages, and it probably worked better with Matthew Kelly who was a straighter presenter and fitted in better with the format.
It's a bit like how I always thought The Price Is Right was Brucie's weakest show because the format was so constricting it didn't give him enough opportunities for him to shine, it was just a relentless procession of games and prizes. His best vehicles were always those with a simple format where he could ad-lib and mess about with the contestants. But it was Brucie who suggested a revival of The Price Is Right to ITV, he saw it when he was on holiday in America and suggested it when they were looking for a new vehicle for him. I know Bruce Gyngell was so happy Brucie was prepared to come to Leeds to film it he turned virtually half the YTV building into his own personal dressing room.
And of course Brucie saw Card Sharks in America and suggested it as a good format for him to do. After that he saw Family Feud, though, and thought that would be a better fit, but of course ATV had already bought the rights and were going to do it with Bob Monkhouse. Michael Grade tried to convince ATV to swap it ("It's very physical, much more Brucie's thing"), but they wouldn't. In the end it worked out fine, and you would probably argue that Family Fortunes was the better format as a whole - in that it carried on for much longer and was still successful without Bob - but Play Your Cards Right was the better format for Brucie because it was much simpler and allowed many more bits of business. And of course they never did it without him.