Thanks again everyone for all the advice..I think I will listen out for a genuine apology when the sales manager calls tomorrow, or will tell them to stick their car.
Absolutely, might just cut corners to meet the price, I.e. No valve measurements.
These cars are rare and good examples more so, to walk away on a matter of principle is a bit "cutting off your nose to spite your face" in my opinion.
Even if the dealer intentionally lied, whilst he's a bit scummy (let's face it most are), he has the car you want. If you were buying a more common or more easily acquirable model I'd say walk away, he doesn't deserve your commission. But for an MC, if it's the right car get it, remember that he's an idiot but be reassured in the knowledge that you'll never have to deal with him again.