The specular textures in the common folder are just neutralized place holders. When you want to use the specs, use the large templates from the paint kit and the size you wish and put them in livery specific folders as any changes would be specific to a livery.
Sorry, I have no plans to change and re-export the 22 exterior and interior models. :-) That would be a good 8-hour job with lots of room for errors.
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