I downloaded the A2A 172 pilot headset mod from the library.  I replaced the 'characters' (dds) file in the 172 main texture folder after renaming and moving the original.  I still get the pilot without the headset.  I tried changing to a different pilot and back.  I tried rebooting.  I don't know what else to do.  Where could it be getting the original pilot (without the David Clarke headset?  Does it cache this somewhere?  Is there something else I have to do or get to make this work?

I cannot imagine adding a headset is just a question of placing another  dds-texturefile.

To get a headset on the head of the pilot you need another 3D file for the pilot ( or just the headset) as well

I got this sorted.  First, the texture files was just that, a texture to add the David Clarke logo to the headset.  To get the the headset on the pilot, there was an option in the settings for the the aircraft model.   (duh)...   I turned it on, I have the headset and new texture applied.  Sorry for the noise.

DM