The Deluxe is the top model from Mountain Goat.  The frame is fillet brazed with the top tube and down tube using ovalized tubing.  The "Loose Leaf" seat binder uses 2 contoured shims that compress on the seat post which eliminates the slot in the frame.  Mountain Goat bikes have always been known for there interesting paint jobs.  This bike features the Prismatic paint which was a $250 option in 1990.  The fork and stem were added at a later date and painted to match.  Definitely one of the prettier bikes in our collection.