I think it was the nickname. Without using FLE I’d placed an asteroid field around NY’s sun and a base in it which was a copy of the Junkers’ Rochester base with some changes to commodities, equipment and a different ship. With this all seemingly working correctly I put those modifications into a folder and started using FLE to continue the mod, adding 4 systems with several bases, planets and fields. Then set about getting the Starblazer to work, getting the LSF able to fly ships and tweeking some items’ stats like getting slightly more speed from an advanced thruster.
What I had done though was copy the mbase entry for Rochester to my new li01_16 base, remembered to change the ids_names for everyone but forgot to change the li0113 bit to li0116 in the nickname.
Anyway, after finding this, I used FLE to change the properties of the base and copied the original NPCs over from Rochester, knowing FLE would change the nickname to suit and then changed the ids_name number to my own. Job done.
Such a small thing to give such a large headache!