'There was a discussion January 1972'
That's it. The complete documentation of one of the conversation works by Ian Wilson in the Panza Collection, as reproduced in Art of the Fifties, Sixties and Seventies the second edition of the collection catalogue, published in 1999.
Only the caption lists the artist as Jan Wilson [ouch]. There are inventory numbers running from IW 1 [above] to IW 13, so it appears Panza and Wilson chatted quite a bit over the years. [At what point, I wonder, does being a conceptual artist working in the medium of conversation start to complicate your daily interactions with people? Are you like Midas, cursed to turn every topic you touch on into art?]
The catalogue includes Christopher Knight's lengthy interview with Panza, but as mentioned before, it also includes a trove of documentation--sketches, working diagrams, specs, certificates, and invoices--for a great number of artists, including several pages of reproductions of instructions between Panza and Donald Judd concerning the fabrication of his pieces. Great stuff.