https://www.google.co.uk/search?q=mk3+golf+vr6+gearbox&client=firefox-a&hs=g6W&rls=org.mozilla:en-US:official&channel=sb&source=lnms&tbm=isch&sa=X&ei=Mh5WU9D5LpOu7Absq4DYDA&ved=0CAgQ_AUoAQ&biw=1280&bih=642#imgdii=_
What might be easier mate is if you post a picture of the bolts that are loose and we can tell you what they are If not I can take a picture of the other halfs tonight
Don't they hold your cables for gearshift in place ?
Definitely not structural.