I have asked the WingWalkers if we could use some of their missions on our server with mods on. this was the reply
No problem, you should have the files already for every map you have flown on your computer in your dogfight/GB_PublicServer folder. You need to start the mission editor and enter the name of the mission's file with the .msnbin file extension as the master file with the .mission extension does not download online. Once you have loaded the mission into the editor with the .msnbin file save it to your computer and that will generate a new .mission file from the msnbin file and then you can load the mission normally.