Glad to hear you found the cause of the oil leak.  As a matter of course, I
would think replacing the valve cover gasket would be standard operating
procedure.  Valve cover gaskets are almost never reused - at least I've
never heard of them being reused.  In short, I would go back to your
mechanic and, at the very least, make your displeasure known.

And while you venting your spleen at this guy, ask him why he didn't put a
phosphate free antifreeze in your cooling system.  Green coolant means it
just regular old run-of-the-mill stuff.  Bad for WBX engines.  With new
heads, you're going to want to put either the VW Autobahn brand blue
coolant into your cooling system, or the orange Havoline or Prestone stuff
that significantly cheaper.  Either way, the green stuff that's in there
now is, from everything I've read, going to ruin you new heads at a good
clip.  (It's all relative.  You might get 50k out of the heads with the
green stuff and 70k with the blue or orange.  Your choice, but I'd want to
give the new heads every chance of going 100+k.)  If this guy put green
coolant in, did he do a system bleed, a la Bentley?  Kinda make me
wonder...

Alan Bosch
& Phred ('88 Wolfsburg)
Rochester, NY