Because you car has an Air Cooled VW motor, it is normal to have a higher oil pressure at first when the engine and oil are cool. As the engine heats up, so dose the oil and the warmer the oil, the thinner it becomes thus, a lower oil pressure. That being said, long idle times, more than 10 min, in a air-cooled car isn?t a good idea. On your next oil change, I suggest not only draining the oil from the center plug in the pan, but remove and inspect the oil screen in the bottom of the oil pan. Make sure there is no debris clogging it and if it is damaged or brittle, replace it.
My .02 worth hope this helps