Sucks you had such a hard time getting it together. When I got my '87, the old man I got it from didn't like the sissy bar because it was in his way swinging his leg over. Removing and saving the bar seemed like too much hassle to him; because the screws are hard to get to, so he just took a hack saw to it! I bet after about a half hour on the hacksaw he was thinking taking the bolts out would have been easier (and it would be). Anyways, here's what one looks like cut off:
I got my new/used bar on by only loosening bolts and working the parts around, but I've had many, many years
of experience or mechanical assembly, and making things that don't want to fit go together anyways. And I admit this was a bit of a tough one. I probably wrestled the thing for 30 minutes with all bolts loose, before I could begin to tighten anything up. Probably would have been better off to take it all off and do it from scratch as Greg suggested, but I figured there was more chance of scratching things up that way. And I'd have felt compelled to tape the fender sides as another poster recommended.
At any rate, on some assembly jobs it just pays to "bite the bullet" and start from step #1 instead of just loosening things and working from the middle of the procedure. Live and learn still applies after wrenching all your life.