Graeme Staples who is writing a book on Motorcycle Circuits and Racing in New Zealand has sent me an artcile on Seagrove in 1949 - Had already posted page one back in April 2020 on this thread.
There were two pages that were published in a booklet called Motor Sport Nostalgia - published in 1989 by Graham Vercoe. There were several events at Seagrove and there is mention of the " Competitors Car Club " and Northern Sports Car Club " [ NSCC ]. What the CCC was I do not know and hadn't heard of it before the article I saw in April 2020.

Cover of the booklet
1949

Name: NSCC 1949 #115 Motor Sport Nostalgia 1949 Cover G Vercoe Graeme Staples (800x600) (2).jpg Views: 1045 Size: 126.2 KB

Here is the full article [ repeating the first page - page 21 ] - the magazine covers many events from 1949, and there was a 1950 edition too -also published by Graham Vercoe in 1989.

Name: NSCC 1949 #111 1949 Seagrove Race Meetings P1 Motor Sport Nostalgia G Staples .jpg (3) (595x800).jpg Views: 988 Size: 182.0 KB

Name: NSCC 1949 #112 1949 Race Meeting P2 Motor Sport Nostalgia G Staples .jpg (3) (567x800).jpg Views: 946 Size: 144.5 KB

Cover of the 1950 edition

Name: NSCC 1949 #116 Motor Sport Nostalgia 1950 Cover G Vercoe Graeme Staples (2).jpg Views: 984 Size: 42.5 KB