I noticed a spot of oil on the heat exchanger.
get new valve cover gaskets, while yer at it, check adjust the valves. :D i reccomend getting the Compleat Idiots guide to How to Keep Your Volkswagen Alive by john muir he was a genius. along with cool detailed fun art it gives you step by step instructions for repairs, maintenance and all that
8 bolts? You must mean the ones around the drainplug. Maybe just snug them up a bit more? Or, get an oil strainer gasket set; and replace that one(which means you have to drain the oil from the engine first, then take off the 8 nuts, remove the plate and the strainer and take off the gasket against the block, wipe the surface clean and put on 1 gasket/ then clean the strainer and put that up and then the second gasket and the steel plate and put on the copper washers and nuts again and tighten them up again. No need for goop or other gasket glue crap as this is normally taken off with every oil change to be sure the strainer mesh is not clogged with crap(I have seen tree leaves in the mesh). The strainer is the filter. That is good enough. (must be so, for the engine that lasts 500,000 miles). Now if everything is tightened up properly it won't leak. The only reason any engine leaks from the crankshaft seals or pushrod tubes is because compression pressure is getting into the crankcase and exerting a force against rubber seals(which were not designed to take any pressure. In other words, you got blow by as driving pressure blows by the piston rings. It is a part of natural engine wear over time and miles. However, the leak you are speaking of though is from someone not changing the gaskets with new ones.(which is basically mandatory for paper gaskets).
Go buy a Chilton's or Haynes manual from your local auto parts store and a set of gaskets and some shop rags. Then follow the step by step instructions on the procedure in question. And wha-la your fixed. The only tool you should need is a screw driver to unsnap the valve cover clips ( 1 per cover ) pull them downward. Remove the covers then wipe 'em clean especially along the edges where the gasket sits. If you have to scrap out the old gasket be very careful not to scratch the surface. I prefer a large dull driver with no sharp edges. Once you have the cover clean and the head has stopped dripping. Carefully rub fresh oil around both sides of the gasket and place it in the cover. Slowly position to cover back in place being sure not to shift gasket position, hold it tight to the head and re clip cover strap ( screw driver again ). You should never use silicone or any other type of gasket crap in this procedure. If done well the leak will stop, Good luck!
Valve cover gaskets. But a word of warning: if you are running those shiny chrome valve covers, there is your problem. They just simply do not have the right texture to hold the gasket. Instead, the gasket gets sucked in and leaks. Regular black covers are cheap and good. And you won't need any gakset cement. Just place them wqhere they go. If necessary put a little grease to hold them in place in the covers--usually not needed. A thin coating of grease on the gasket surface will held keep it from bonding to the head. Be sure the head surface is clean before putting it together. Check the cover for flatness against a flat surface while it is off. You may be able to tweak it back to flat--otherwise replace.
