OK Roger,
I have it in my mind that Ron Roycroft ran the Bugatti rather than the Alfa and this could account for his name being crossed out. I can't recall the Alfa having being used in a hill-climb. Whatever, I could be wrong.
Without doubt the open wheel buckler entered, was the first in New Zealand. I can't remember it at the event and I would say that it did not show. What is more, I can't recall Arthur Harris ever driving it in serious competition, with this at first being left to his son.
During those early days, crash hats were in short supply and I did not own one. During the running of a hill-climb, a car would return helmets to the finish in order to facilitate the their loan.