I think you are on to what I am thinking. I was able through Classmate’s web site to get Northam’s 1977 basket ball team photo. I was able to do a screen shot and copy just the men’s basketball photo which shows Northam in the back row. There is black team member, also in the back row, if you draw a line from his lips it will hit Northam’s eyes, just as in the KKK photo. I think we have a match FRiend!
The Classmate photo:
https://www.classmates.com/siteui/yearbooks/4182831803?page=71
Northam said he wore a Michael Jackson outfit.
If you look at the blackface photo. Mirrored glasses. A white fedora with a black band. Both michael Jackson clothing items back then.
I do think the KKK person is likely his date given the height difference. This was likely the date photo taken at parties when yuh first walk in.