I haven't been able to work out how to create an fueling station on the Moon (for example) using the Launch Tower Assembly etc. yet, but I have been able to create one in orbit! I don't think it was intended to be used that way - just pretend it represents routine fuel deliveries to orbit.
Self-fuelling tank (using Neptune's Big fuel tank and 2-wide, it also uses 'Pioneer' and 'Griffin' engines ('Griffin' in the launcher) - not quite sure which custom part they are from):
Attached to station:
Designing a launcher for it was a bit tricky since the payload increases during the launch (it refuels continously). In the end I designed it with first stage assuming empty and second stage assuming part full. The tank itself was the third stage and can use the fuel generated during the launch:
Maybe you could create a variant of the "Launch Tower Assembly"+"Umbilical Cord" intended for stations? Initially with fuel generation switched off and can be switched on without rotating the umbilical?