Elspeth,
Please email me at fam dot hist at yahoo dot co dot uk.
I have driven past Longbeach and also along Jaines Road near Ruapuna, and also visited the wee church at Ruapuna which was started, I believe, by Charles Jaine.
I'd be very interested in exchanging deatils, and perhaps arrange a visit for when we next visit NZ - our son lives in CHCH!
Best wishes,
Philip