I have now checked my original source, which is a forum populated by enthusiasts from Down Under. There is no mention of Bill Kyrkwood, but I agree that the site does not categorically state that Vin Smith built the car. I rather assumed that was what had happened.
Anyway, your posts more than adequately identify the car, and the point is yours. From the puzzles you have solved up to now, you are clearly someone from that part of the world, and are a welcome addition to our ranks.
This is a photo of the car later in the 50s, when it had the attractive Maserati-style body modified, and now had an MG-style grille.