OK. This is the definitive story from Doug Nye's BRM Vol 3.

Three cars came to NZ in 1966. Two centre-exhaust models 2616 for Hill and 2617 for Stewart. A side-exhaust model 2614 was a spare.

Stewart's car was delayed due to shipping problems so he used 2614 fitted with the windscreen, steering wheel, seat and pedals retrieved from the ship-bound 2617.

At Levin Stewart used 2617 and Attwood was in 2614.

Stewart decided to try Attwood's 2614 at Wigram and liked it so much he used it in the race. Attwood raced 2617.

At Teretonga both used the cars they raced at Wigram.

Stewart was number 6 at every meeting and Hill at the GP and Attwood at the other events carried number 2.