How to open a .bmp thats already converted???

I am repainting the Milton Shupe D18S and there are a few things that I cannot open that have that funky striped look to them. I have DXT3 and PSP7. Can I reconfigure it to be a repaintable .bmp?
Flight Simulator and other chat
https://forums.simviation.com/phpBB3/
https://forums.simviation.com/phpBB3/viewtopic.php?f=15&t=35775
lol I like that 8)that funky striped look