Camshaft/drive train condition - 560SL
 

Got both valve covers off in preparation for servicing the oiler tubes and chain guides. See photos below. First two are of the driver's side. Second two are of the passenger side. Note the one rust area in the same spot on both camshafts. Also note the areas of corrosion on the rocker arm supports (I think that's what they are called). My guess is that the corrosion is from long periods of inactivity allowing all the oil to drain off and let some moisture start taking over. The areas of corrosion seem to be able to scrap off with my fingernail. Is any of this anything to worry about? Any actions I should take before closing everything up?

As long as the lobes on the cams are in good shape and the rocker arms not worn at the rubbing point then no worries. I would make sure you clear up anything you scrape off so it doesnt end up being circulated around with the oil. Also, try rotating the engine until the notches on the front of the cam line up with a notch on the front cam tower, this is TDC on cylinder 1 and both cams should have the notches lined up at the same time with the crank timing mark close to TDC as well. This will indicate how stretched your chain is. Do a search and you'll find posts about acceptable and unacceptable amounts of stretch.

Thanks Gary - lobes look very good. I'm in the middle of replacing the chain guides and we did rotate it to TDC and all the marks line up nicely, so no stretch to speak of. Just going to do the three upper guides and the tensioner.