Anonymous has resolved Question Time #87. Well done.
It is indeed the Aero L-29 Delphin. This particular very tidy one is ZK-JRF c/n 892851 and was registered here on 30-10-2007 to Wairakei Holdings. It has yet to be assembled and flown.
If Anonymous would care to contact me off blog (address in blog header photo) then I will forward a chocolate fish your way. Bluebus is on the road for the next three weeks so there will be some delay in delivery.