Simply j'adore! The malevolent glee on dude's face - as well as his early '80s blowdried locks - and the distressing POV sell Unholy Mourning (Dell, 1982) completely (thanks to Evans Light for another great scan). Author David Lippincott wrote a handful of other genre novels but would you believe his primary career was as a composer?! Go figure, right?
Sounds like pretty generic supermarket checkout horror fic, but... Jorbie? I'd still read it though.
OK, this is the 1983 UK edition from Corgi, and you just know that's stepback cover art under the cover, you can see there the terror-struck eye, but I can't find the image anywhere... Argh!
Update 5/25: Thanks to a FB pal, here's the stepback for the Corgi edition!