Hi,
I sold a BV 206 a couple of years ago to a Hagglund fanatic named Bill Feeley in Montana. He mostly does custom rigs using Hagglund running gear, but also has a large supply of used and reconditioned parts and such.....might have the info you need.
http://www.extremehagglunds.com/used.html
edit: He shows some tow bars 3/4 of the way throught his "take a tour" video on his main web page.
Thanks, David