While I don't disagree that out of tolerance valve guides drink a bit of oil, I do happen to think that if the oil consumption is not a problem and the seals do a fair job at reducing this - the cost of a valve job in this engine is simply too high for the benefit.
I would check to see if the new valve guides are a different materail too, otherwise in 50 - 100K miles you will end up the same problem.
Hope this helps.
Joel

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Joel P. Davis
1992 500SEL