Welcome to the Yamaha Forum and Congrats on your new/old tractor.
From my research, the 6700 was only made in 1990. I would highly reccomend getting a
service manual. There is a post called "Fast Moving Parts" which has a link to where you can get one.
Baggers are hard to come by, unless you can pick up a used one from somebody.
Good Luck with it.
Rattosh51
YT6800 S/N 821
St. Paul, MN