Geez Ted, just a blurry video with nary a registration in sight and a quick glimpse of an underwing serial ("WK5??")!
OK, the ex-RN Chipmunk is ZK-SKH, (C1-0547, WK511, ex G-BVBT) while the aircraft in the London UAS markings is N861WP (C1-0748, WP861, ex N65273).
The fascinating thing about the NZ Chipmunk scene is the high proportion of the quite rare DHC-1A's that are present (the original Canadian-built Chipmunk, only 62 ever built), out of a total of 22 on the register (plus N861WP, no less than 7 are DHC-1A's. Compare this with Australia with 50 Chipmunks and only one DHC-1A.
As for the aerodrome - as both of the above Chippies are based at Masterton, so that's my guess.