hI,
I have just replaced the rocker cover on my 8v gti with a mk3 aluminium cover, and when l looked at the head l thought that someone had machined it off. Probably was on the origional head casting but not required (i.e. to save money by using less parts) or it interfered with something or caused premature damage to the cam shaft or something
dont worry it should be like that ....phew