Recall... You can do the 'Super Valk' mod, ala Big BF (
http://bigbf.com/bigbf_shop/mod_i-s_trunk/ ), but being able to replace with the sissy bar, is another story. The Standard and Tour, use the same 'Fender Rails', that allow for the use of a sissy bar. The Interstate however, uses a special set of 'Fender Rails' that allow for the trunk to be attached... I've added the trunk to my Standard, but use Interstate Fender Rails... I can remove the trunk, but have no sissy bar option.
Black Dog