I remember hearing about this at the time from someone who knew one of the people that got access. The owner of the warehouse passed away and none of his family knew anything about the property, and it had been untouched for 30-40 years (as you can see from the state of it). One of the family went to look at it, opened it up and went 'OMG!!!'.
I tried to get a lead on it but was told it had 'gone', presumably because they knocked it down as it was semi-derelict.
Something about a rare Psych record that was $500+ and there were boxes of them, untouched boxes of the Skullsnaps LP (which came out on EMI France at the time of release so could be right), and many other finds. Evidently with the Psych stuff in there, if it was all put on the market at once the arse would have dropped out of it for collectors price-wise. Guess we'll never really know!
cheers Sutty