I understand, I was looking for a jpg or png picture

I have added the theater terrain in Tacview 1.6.4 beta 4. Unfortunately, none of the pictures provided are matching well enough the terrain coordinates to be easily added to the custom texture file. It would take too much time for me to find the perfect coordinates.
When Tacview 1.6.4 will be published, feel free to copy/past the coordinates from Data-Falcon4Theaters.xml in CustomTextureList.xml to see if you can find a good match. (I do not give you the new xml file here, because I had to improve my code to load the Nordic theater despite incorrect metadata)