Wishbone....how many?

Ok so, i hear that Wishbone Ash has been around for quite some time.....but during shooting this gig, all i heard were songs being played by; Wishbone3; Wishbone 4....and so on. How many line-ups were there of Wishbone Ash?!
Anyhow, they played up to the camera, which is always a good hting, stops us togs from getting a little bored! :p But noetheless, it turned out to be a good gig, despite lack of crowd.