This is a scenario file that have some station modules from different addons with a fuel tank.
In need of certain flexibility to manage fuel depot on the MTSS (Moon Trip Space Station), some spacecraft3 vessels had been converted using the sc3conv.exe utility to a .dll type vessel, removing the spacecraft3 limitation of 10 vessels per scenario file; the rest of them, being only a .cfg and meshvessel, had first translated to a "formal" spacecraft3 .ini file and then to .dll converted.
Also, because of the unrealistic (to my belief) weights that some of the vessels have, the new .cfg files were modified with a new empty mass (just nice numbers).
The new vessels have a fuel tank that although unrealistic allows fuel transfer between modules and docking vessels.