I have two John Deere Bagger Chutes that I acquired through another purchase that I don't need.
The chutes are 40-47 inches long depending on where you measure from tip to tip/end. They are very similar in dimensions, each with a round shoot opening diameter of 7-7.125 inches where it attaches to the bagger unit. The bottom end of the chute where it attaches to the mower deck has an opening of roughly 13.25 inches x 5.25 inches. Although the tubes are almost identical, there are slight variations in certain dimensions of roughly 0.125-0.25 inches.
I have attached several pictures for you to examine.
Let me know if you're interested. If you only need one of them that's fine - I don't need to sell both of them together.