I have had a look through those registration books in the areas where I thought they might cover 1967 without any luck. Unfortunately the numbers aren't issued in sequence which doesn't help. I will look through some of the others when i have time but a contemporary pic showing at least a rego prefix would help a lot as the books have to be scrolled through page by page. Internet search hasn't turned one up as yet.

1966 Triumph Thunderville
1970 TR6C