unfortunalety i can t get rid of LOGOS that aren t needed as the logo is on the main textures
No, it's not. As you can clearly see by opening the Catering main texture folder ( FSDT_Catering\texture.01 ), the textures do not contain any logo, there's just a blank vehicle.
Assuming you want to use the LUX texture added in the last update, that configuration you made won't work because you still haven't read the PaintKit with enough attention. From Page 5 of the PaintKit Documentation:
The 5th Fallback is likely the most important to understand properly. We are finally referencing the folder containing the actual Logo user texture.
This is the folder that contains the GSX_Logo_4x1.DDS you can create for your Logo but, why it’s under the FSDT_Staircase folder ?
It’s just a convention, we need to choose only ONE Simobject folder that will act as a “Storage” for the actual logo textures, with the others just referencing through Fall- backs. We chose to use the Staircase for this purpose, it could have been any other object but, since the rest of the set provided with the PaintKit uses this convention, it’s best if you stick to it, otherwise you would need to modify all the other texture.cfg of the PaintKit, with no particular benefit.
I don't see how this could have been explained any clearer. Just check some of the OTHER TEXTURE.CFG files for Catering vehicles that comes with GSX which have a texture that ALREADY EXISTS (meaning, it's not Catering-specific) as an operator for other vehicles. For example, the one for Air China, in the FSDT\Catering\texture.CA folder, look like this:
[fltsim]
fallback.1=..\texture
fallback.2=..\..\FSDT_Marshaller\texture.red
fallback.3=..\..\FSDT_Marshaller\texture.01
fallback.4=..\..\FSDT_Baggage_Loader\texture.01
fallback.5=..\..\FSDT_Staircase\texture.CA
This because Air China is already an operator for all other vehicles types so, as explained in the PainKit, its "master" objects that contains its actual Logo textures is the FSDT_Staircase folder so, the same is valid for LUXAIR: since we HAVE it as an operator for all the other vehicles, its logo is under the FSDT_Staircase\texture.LUX, so that's what you'll have to put inside your texture.cfg.
And, of course, you must have a custom texture folder+texture.cfg for all different variations of the Catering vehicle, and the according [fltsim.xxx] sections, each one with the proper ICAO codes.