My post seems to have vanished.
I had said that Brundle gave Senna a run for his money in F3, went well in the N/A Tyrell, when everyone else had turbos, but never had a decent break in F1, and whilst quick for Jaguar, some of the ex touring car drivers gave him a run for his money, but he was quicker than Dell Boy Warwick, who had been lucky enough to sit in a F1 turbo Renault
I'd add that I must finish reading "Crashed and Byrned", as Byrne could beat Senna, but had even worse luck finding a drive. Those were the days. Byrne won a test drive with McLaren, and of the four tested he was fastest, even after they'd turned the power down on the engine management. He's upset Ron Dennis, who thought he was an idiot that would crash the car.