It was barely longer than the FiST, lens on the camera made it look far bigger, it is tiny! Not sure which model but you do seem to know your McLaren's!
Notice the brake dust, garaged at the track, hard to imagine taking a car out like that....I have huge respect for those with the money and the balls to do so.
Craziest cars from the era were Shadows, insane!
Got to a historic race if you love cars, walk in the pits, talk to the owners which many are cool enough to talk to.....I have watched a Bird Cage race and talked to the owner, never will forget it.