Original Engine Bay Paint Marks "KLK"

[Car54280ZX]

Can someone help me identify these marks?

The marks, hand made in blue-green paint, says "KLK." It has been there since the day I purchased the (S130) 280ZX,  brand new in January 1981. Manufacture date is September 1980.

I have no clue what it means or who put it there. But, I believe it was painted in the factory. I say that because there is one other short paint "line" of the same color and brush width on the end of the valve cover at the firewall (see photo). And, another painted circle of the same color and brush width on the top front of the valve cover (see photo). And another attached photo shows just the KLK paint marks (delineated by the white arrows).

Does anyone have any thoughts on the history of placing paint marks like this? Is there a value to keeping the paint mark? Does any original owner have a paint mark like this under the hood? I'm very curious.

Please help! Thank you!