Have you tried your favourite FS9 versions? This Cessna 150 Aerobat works in the FSX Demo.
http://www.simviation.com/fs2004props20.htmThere are lots of repaints available for it.
PS. The registration doesn't seem to display on my system. That's no big deal. IMHO
The only trouble I find is that most/all of my desired FS 2004 aircraft have their gauges, etc aliased to the contents of the FS 2004 Gauge Folder, and it involves a lot of work...

...tracing them and copying them into the FSX Gauge Folder...

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I have my favourite CC-KAA and CC-KDF 152's copied into the FSX Aircraft Folder, but of course, all the various gauges, (and some views, textures, etc) are missing 'cos they are in the FS 2004 Folder...!!
(and that is really too large in total to add to the contents of the FSX Gauges Folder).
In FS 2004 most of the add-on aircraft use the default FS 2004 gauges...so no problems there...
The only other option is to install, when available, the aircraft especially designed for FSX, (which may include the necessary, non-default gauges, etc), aliased to the default FSX gauges, ...

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Cheers...!
Paul... 8)...!
Note: I have both full working versions FS 2004 and FSX installed and running on my HDD.
After-thought....is there a way of aliasing my FS 2004 aircraft gauges in FSX, to the Gauges Folder in my FS 2004...(if you know what I mean!)...

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Win 8.1 64-bit. DX11. Advent Tower. Intel i7-3770 3.9 GHz 8-core. 8 GB System RAM. AMD Radeon HD 7700 1GB RAM. DVD ROM. 2 Terra Byte SATA Hard Drive. Philips 17" LCD Monitor. Saitek Cyborg X Fly-5 Joystick. ...and a Briggs and Stratton Petrol Lawn Mower.