Terry,
AG and KG are the same thing, different countries but it is KG as per the d/b
No idea on GAS, don't think its the same company as no aircraft are mentioned on their website and as far as I am aware they are an FBO, got it from my d/b, they also had 2 Learjets previously. As Eurocontrol have DC aviation as the operator I will change it the other way around
Thanks again
Alan