I have a 78 KZ650 D1 also, had the compression checked a couple of years ago with similar results to yours ans it runs fine
#1 130, #2 135, #3 130, #4 135
I've owned the thing for 30 years and it has alway weeped a little oil in the same area as yours, I retorched the the head bolts to spec and cleaned it up with Gunk, but a little still comes comes out. The head has never been off it.
78 KZ650 D1
