Hi Murray, I was browsing through the Forums and came across your profile. My wife was born in Timaru and her wider family live in Temuka. Her other sister married a Maori elder and they live on the Arowhenua land. They're over there now enjoying the Kiwi summer before returning home for the English summer. Work prevents me from going this year.
If you're ever in the UK you have a place to stay.
The E38/39 steering wheel with buttons can be fitted. There are two problems to be sorted in your design:
1) Air bag connections. Single or duel stage air bags
2) Slip ring connections.