I refilled it with Mobil 1 Supersyn SL 0w30 (for the winter near Rochester NY)....I'll do another UOA in about 7K and let you guys know how it goes...Thanks for the thoughts...
PS: I'm not gonna sweat this too much because I think it's an anomaly due to changing oil brands (types). I was pretty impressed that a 15 year old SJ rated, 99 cent a quart, dino still had 2.4 TBN after nearly 7K (albeit mostly highway miles)...except for the copper, this was a very good UOA...
Copper can't be formed by a chemical reaction, it's either in the engine block or oil cooling system already or it's a contaminant (This engine does not have a turbo which along with an oil cooler is a more normal source).
There are a number of greaes used on various systems like the brakes that have high levels of Copper, BUT I can't think of any sealant that would be used during a normal or cam belt service that has grease in it. The sealants often show up as Silicon.
I think the most likely reason is that at some point in the cars history someone added Copper seal to the coolant to help stop a leak. Not sure how many coolant system additives apart from HG sealers have Copper in them, but that seems the most likely source.
All it then takes is one small pin hole in the HG for the Copper in the coolant additives to cause a jump in the UOA figure.
The UOA shows a bit more Sodium that might be normal (Check the VOA figure) for an anti foaming agent and although the 15 ppm figure was for the last OCI, the pin hole or small crack in the HG might have not started until near the end of that OCI.
Was there any Potassium in the UOA, as that is a good marker for coolant ingress, although not all anti freeze contains it.