HuDuGuru.... you are absolutely correct!

I re-read my log books.... my mistake, I misinterpreted the entry .... Oct , 2010 "...lapped valves....reassembled and resealed engine...". I mistook "resealed" as putting it all back together.

So...the puzzle continues...since I bought the plane it has used oil at a very consistent rate.... approx 4 oz every 3-4 engine hours. Compression is great, differential pressure is great (see below). No leaks whatsoever. Engine runs great!

Spark plugs from cylinders 1 and 2 are dark, but not fouled, cylinders 3 and 4 are nicely tanned. Seems to indicate valve seals in cyls 1 and 2..... or something more insidious.

Any ideas?