Seems like a silly thing to ask but do the 955i parts fit on the 855i? I have a 2000 855i and parts are a royal pain in the arse to come by.
http://www.worldoftriumph.com/triumph-motorcycle-parts.html This might help. Look on here and compare part numbers
Welcome to the forum! You've come to the right place to ask questions and find a few laughs. It will take a little time to compare numbers, but Sprinter gave you the right answer. Once you have the correct part number, you can just Google it and see if anyone has what you need on E-Bay, etc.