akront rim

Akront Aluminum Rim 18" 1.85-40-TR-1095 Spain NOS...would this be a good fit for my khk rear?

Oem rims are 2.15"

Harley Aluminum rims are Borrani, not Akront, although either will work. The spoke angle needs to be correct and it needs to be a WM3. H-D didn't use any until '60 so I guess you know it is not correct for a KHK. An early 70's drop center type also works but the best is a stock early Sportster one (43008-60). Real KR rims are usually 19", Sportster are 18".
Robbie