I never tried altering the "StrTactMap.tga" image size before so I had no idea as to whether it would cover the gray area or not, I did just try & seems to have no effect (except possably the 30 mm). So a little more research is required, but I will be tied up for a few days before I could even think of taking a closer look, if your still stuck by then I will certainly try to help.
Cheers.