I saw an auction ad for "PSION ORGANISER II LZ64 IN VERY GOOD CONDITION WITH OPERATING MANUAL." at what seemed like a good price. The seller has multiple units for sale. I queried Martin about the seller, "lepowerfulpierre", and he turns out to be "thesourcerer"; a well-regarded member of this forum. Martin suggested I contact him through the "Shop" section in case others are interested.
I ended up purchasing through his auction listing but I wanted to follow through on Martin's suggestion about mentioning it here so others that may be interested are aware of the listing and can contact him directly. I'm looking forward to receiving the LZ64. I'm in the US so it will take a few days to get here.