This morning I was looking at what could be done with the default Reeve (Waiheke) which is in the wrong place and should really be NZKE, not NZRV. First move was to disable APX94450.bgl, which covers airfields from Waihi across to Auckland and up to Coromandel and North Shore. Since most of the smaller ones were already in as Add-ons, I wasn't too concerned about disappearing the defaults, and I soon found Add-ons for North Shore, NZAA, Coromandel and Mike's WaihekeX
As a bonus, disabling that bgl seems to make Supercity load more quickly, but I don't know why. Very pleasing, anyway. A downside was losing the facilities from some airfields, but that shouldn't be hard to fix. Also, the related CVX file will cover those same airfields, which stops me just taking out the Waiheke one.
Mike has certainly nailed the terrain, with the help of some well-placed trees.
Default (with VLC)

APX94450.bgx

WaihekeX

