Jetranger here 
 my experience with many HJG Jet Aircraft has been good and I have several of their Jetliners in my FSX Gold / Acceleration. 
as per the Read Me file instructions with each aircraft,,,,,,,,,, 
read it carefully,,,, you almost always have to as per instructions - change both the PANEL CFG File names , it clearly states so in the instructions -  
as I recall,,, you have to change the 2004 and the FSX file names of the Panel CFG File,   
this is where some have a lot of problems and mis understanding  
*** FS2004 users) Proceed to step 4.
   (FSX users) Enter the folder "PANEL.B707-138B", and -  "rename" - "panel.cfg" to "panel_fs2004.cfg", then  - "panel_fsx.cfg" to "panel.cfg".  
the above is very important with about ALL HJG Jetliners , very important if you want them to show correctly !! 
simple procedure really,, once you learn the in & outs of it and get used to it. 
I have some of their Boeing 707's 
and 727's 
Convair 880 & 990 jetliners  
as well as their DC 8's  
Jetranger - with around 4,900 Aircraft injected into my FSX Gold / Acceleration  
 
  