If anyone is interested, the duet sets that are out of print can be purchased directly from Kjos for $10 each. You can either order them by phone at 1-800-854-1592 or by email at firstname.lastname@example.org. The duets are in the ARCHIVE so you must give both the tile and the catalogue number when ordering.
Eight Lighthearted Variation on The Jolly Miller (GP504)
Our British Cousins (GP514)
Fantasy on Three English Folk Songs (GP503)
A Western Summer (GP515)
Two Below Spreadeagle and Partita have never been published. I can provide you with a performance ready pdf if you are interested.
From Sea to Shining Sea, The Blue and the Gray and Spanish Dance Fantasy are all still in print and readily available.
Thank you for your interest!!!