Weird timing... I was also looking around the internet to see if Jurgen was ok. I last talked to him in December - I have bought just about every kit he has ever made and recently bought the MM/MC phono amplifier from his site. He usually responds quickly but I haven't heard anything and thought that was odd. I had also emailed him about a week ago regarding the fact that my clocks that sync up with the wireless GPS puck all started showing the wrong date (1934) about a week ago. No response to that either - which is highly unusual - Jurgen is the type of guy that responds within hours to seemingly every email!
I didn't realize he was sick - but hope that he gets better soon. His last post on facebook was Jan 16th.
I don't have any "inside scoop" or "direct line" or anything so I too looked around a few places he's known to hang out online. No sign of him recently, but I found no "where is he?" threads or any explanations or anything.
I recall he disappeared for several months a couple years ago. At that time somebody (?) told us he was sick and in hospital. Jürgen eventually reappeared here but said nothing about what happened to him.
Look into it later when the dust is clearing off the crater.