The B22 is one of the rarest Aurelia saloons, only 1074 built, it has a 1991cc 90Bhp engine.
Brin Edwards car is a B21, with the 1991cc 70Bhp engine.
I think the only way you can tell them apart, without opening the bonnet (including the B10 saloon) is that they have different top speeds on their speedometers!