I got inspired by two bricks moc, and decided to mod my 75257 using some of his ideas. I may continue with mods, but any more work and it's really going to be its own set.
list of mods: hull redesigned: uses ball and socket joints instead of hinges and slides forward and back in two parts (instead of 6); cockpit can fit 4 minifigs; cockpit moved forward and out to fix gap; a little bit of greebling; modified landing gear for wall mounting