Broken savegame from alpha 22

[DaleStan]

TTDPatch 2.0 alpha 22 managed to write this savegame (ttdpatch.cfg and newgrf.cfg included.):
Go take a look at Darninghall Transport's Aircraft 4.
Not in the aircraft list? (It isn't, but there's an empty slot for it.) Try clicking on the nose sticking out of Gethill Airport's hangar.
An earlier load had broken graphics[1][2], which I thought I had fixed by disabling and re-enabling the DBSet and DBSet XL (in the correct order).

I have SV1Codec, TTDX Editor, a hex editor, and the savegame internals.

I've tried everything I can think of to get aircraft 4 fixed (or even just gone), and aircraft 5 out of the hangar. This includes "Cht:resetvehicles", attempting to reset aircraft 4's data, removing the aircraft, removing its shadow, and setting the airport to "not busy"[0]

I've managed to make the aircraft un-click-able, and to remove its slot in the aircraft listing, but the nose stays put, and aircraft 5 stays stuck.

What am I missing?
I'll continue to play this game, so I'll need to know how to fix it, but I intend to buy out Darninghall Transport sometime soon[4], and I don't want to own a stuck plane or an non-removable airport.

[0]I've tried counting bit 7 from both ends of the word.
[1]And I had NOT changed newgrfw.cfg. The only thing I can think of that I did do is un-install[3] the Traffic Set 2.0
[2]Most notably that both (buildable) aircraft had stats that match what aircraft 4 has.
[3]by way of (a)replace original .grfs (b)reinstall everything else (both conveniently stored in an .rar)
[4]==AFTER fixing its brain-damaged train and airtraffic systems