I used to wheel a bit with a guy in the capital cruisers, robert renediu? He had these on his 80 and while I was skeptical of their worth them seemed to do a really good job. Obviously they can't take big hits from rocks and trees etc but your going to get damage without them in the same senario if you ask me. It keeps the little to moderate stuff from damage which I do think it works. I'd was actually hoping I could get or make a set for the 70. I think the biggest issue is the way the clamp is used to secure it to the bull bar.
I dunno if I like the look on the 80, I'd pull the fender flares if I had one
But I don't so I can armchair wheel your 80