I have noticed on quite a few custom airfields (not FSDT and certainly not even half the others, but enough to raise it), when selecting catering services, you don't get a prompt for which company you'd like to use.
Whilst for some custom airfields, that's because it's already coded and you get a specific company, which is great.
The issue is, for many other custom airfields, you don't get a choice and you get unbranded trucks.
Is this an issue with the GSX profile for the airport (ie a null field somewhere)? Is there something you can do in the code that will force the selection menu rather than turning out unbranded trucks?