This file contains and FSX.mdl folder, an aircraft.cfg file and a Curtiss_Jenny.air file. If you have FS2004 then you already have the Jenny but if not then at Simviation.com there is a file called Jenny11.zip which you can download and use for this project. It also contains a number of additional repaints which are included in my replacement .cfg.
The new FSX mdls were created by Michal Puto and are offered here with his permission. The Jenny (and the DC3) were offered open source in the FS2004 sdk and revised versions of the DC3 have already been uploaded elsewhere.
Simply drop the new Jenny files into the FS2004 folder and overwrite all the existing files to have an FSX native aircraft.