The way jetway replacement is done, should clarify why you can't do anything with jetways, because they are inside the 900+ .BGL files we supply GSX with. We have an automatic system that compiles all of them according to the normal GSX jetway/operators rules.
A more useful suggestion would be opening a thread with a list of airport and what the correct logos would be, so we can update our rules files, regenerate the affected .BGLs and place them on the updater.