However the DR1 was not embedded.
Looking in the texsrc folder you can see the htx files for the P51 were created by the terrain editor, but not for the DR1.
I've noticed that the WWI plane textures use a different naming convention than the WWII planes I've seen. WWII planes will be "<planename>.bmp" where the WWI planes would be like "<planename>_1.bmp".
So out of curiosity, I took the texture I marked and named it "DR1.bmp" and lo and behold the terrain editor recognized it and generated a htx file!
Of course this isn't a solution because the model will not load it. So whatever scans for files <planename>.bmp to convert to htx is not looking for the same file the DR1 model is looking for.
I don't know if there are any WWII planes (newer than WWI?) that have that different naming scheme, but if there are, they might have problems too.
(Attached is the test terrain and bitmaps in texsrc.)
,
CptTrips