Once Cees finds out where exactly it is, and if it is accessible, I am happy to put up with ... er I mean put up a group at my place then take them over there to go digging. Grant knows the Takaka area reasonably well. We could do a day trip from Blenheim. It takes about 2 and a half hours to get from here to the top of the Takaka hill.
Too far for a conference bus trip (and very windy - as in winding roads, not strong winds) but easy for someone who wants to stay a day or two extra and do the trip then (a lot harder to dig in the frost though!).