Blackstone team, thought you would be interested to know the following: the origin of the 200% increase in nickel was valve related. Your suggestion to check compressions and possibly borescope were right on! Five cylinders, seventy plus, and #6 was (almost) twenty lbs. Didn’t need to borescope to find the problem child. After removal of the cylinder the exhaust valve was obviously the issue. Colors like a Christmas tree…dark at one side, then dark green, then green, and finally sunset red. The mechanic estimated failure within fifty hours or thereabouts. That cylinder had over 1600 hours time in service. Since the annual and compression checks were six months away…your analysis saves me from unexpected maintenance, probably occurring far from home base and who knows what else! Thanks again.