what Right side front brake caliper works on 1980?

reviving a KZ twin.

I want to upgrade front brake to dual disc arrangement. Did a fair anount of looking and couldn't find parts diagrams with part numbers so I could determine what bike(s) would have the correct right hand caliper.

Looking for list of compatible bikes or reference to website that still has the parts drawings with part #'s so I can figure it out myself.

thx in advance for help.

Have a picture of your current one? Is it early 76-77 style with the threaded pipe screwing into it, or is it the style with the 79-80 banjo fitting screwing down flat?
You can use the same calipers. You just need the opposite side bracket. The brackets are not interchangeable.
There are always used calipers on ebay. but you always have to take apart and clean them. And hope the piston is not pitted.