While the marks could be a lot of things, the "upper engine lubricator" may be a possibility Tim. Here is a
line that has also been a mystery to me - this line goes around to the to the oil filter on the other side, and I have no idea why. Haven't seen an engine picture that shows one like that , unless I'm just missing it, but if it was connected at one time to an "upper engine oil filter"- (which would have been close to this) that would made sense. Have you seen a setup like this that I'm showing?
Dale
