After looking at how difficult the bolts are located I contacted another garage, got an appointment on the 21st.
I explained him the situation and he told me they could change the gasket without removing the top.
He also said that the oil that was gathering on top of the intake was caused by the "brown" plug on the front of the carburator, he told me this was a common problem and that this could cause irregular idling, he advised me to clean this plug regularly with some compressed air to avoid any problems.
I asked him how they would confirm if there really is a leak in the gasket, he said they would spray around the gasket with some "starter spray" to check if the rpm would jump up.
I did this myself, infact a sprayed it on every vacumhose aswell as the gasket and the rpm stayed stable.
Could this mean that the gasket is intact

? Maybe the other garage was trying to rip me off

.
Would it be a good idea to unbolt the intake hose from the carburator and clean it with som carburator cleaner ?