I'm curious if you have considered, amongst whatever other resources you have available to you, sending a picture of the pots to Yoshikawa Toko at Artistic Nippon or to someone like Hojo, whom also sees many different Japanese clay works and works with potters there in Japan. I was tempted myself to send a screen shot of "mystery teapot" to the above-mentioned people but didn't want to overstep my bounds with an item that is not mine.
I've really enjoyed the mystery and stimulation of the pieces and the ongoing conversation that the pieces have created. If it was a drunken potter that created the set, then to me the potter was clearly practicing drunken-style gong fu when they were made
: the set has such a wonderful presence, however it was created.