If you want to use an old .txd file with this mod, you need to edit your old .txd file with 
MagicTXD and you have to add these four textures:

1) flapsdown
2) flapsup
3) geardown
4) gearup

Compress these textures in DXT3 with MagicTXD

Now, you have to replace 'screens7b' texture with MagicTXD, compress it in DXT3 as well 