I also had no cockpit on the 350-1000. Virgin Atlantic livery, Virgin Atlantic cabin. Uninstalled cabin pack #2 from ini manager, no change. Changed to default livery/cabin and now have cockpit.
I did update the liveries in inimanager as well as the aircraft.
This is in SU4 beta if that's important. Not sure if this is a SU4 issue.
Thanks,