Yes, there does feel like there is a bit of a ring ridge, but this could be due to build up of residue in the part of the cylinder wall rather than wear, as the cylinder, to my untrained eye looks to have very little wear at all. I'll soon have access to the type of micrometer that you would measure all the specs on the various engine components. This will give me a better indication of how much wear has occurred.
At the moment the engine is completely pulled completely to individual pieces. Crankshaft out etc. I took one of the compression rings and put in down into the bore of its cylinder to see the gap at the ring join. It was about 0.5 mm. This surprised me how much this was. Either the cylinder wall or the rings have had significant wear. Hopefully it's just the rings.
As far as the engine life is concerned, I have no idea. I found the engine is the world's filthiest shed that had about a hundred different BMW and Mercedes engines scattered amongst an equal number of every other bit of the same cars. Suspension components and drive trains were stacked up to the ceiling. The men who worked there spoke no english, and therefore I had no idea of the engine's age. I suspect it's an early 00's engine. Some of the date stamps on the components are late 2000.
Where I live is a little easy going with the way they fix cars. Across the road from the place I bought this engine, was another BMW parts place. They had half a 7 series body there for sale. Obviously it had been in an accident. They got an angle grinder, cut it in half, and were selling the good half. Find another half, get it welded together, and hey presto, new 7 series body. As you might guess, there are a lot of bent cars driving around here.
In a nutshell, they would have no idea of the engine's history.