Loren writes:
>>3)  The radiator!!!  I fought cooling problems for years on my '85 Westy with all the 'experts' (NOT on this list, local VW shops) jumping to the conclusion it was leaking head gaskets:  "These things are famous for that problem".  It was a partially clogged radiator, and eventually cost me an
engine. The reason I bring this up is I have rarely seen people suggest radiator problems as the cause of overheating and coolant overflow.<<

I second that, trashed an engine fighting a bad radiator as well.  Remove radiator and have it flushed/flow tested/leak checked at radiator shop...usually about $30 if you bring it in, new can be had for $200.

JB