Having done an oil analysis on another car once I decided to do one on the Rover if only to set a benchmark. The only anomaly is Lead at 89 , assumed to be parts per million (ppm). Most likely from bearings. Everything else is good - water, fuel etc. It has either 216k or 316k kms. It behaves like a tired engine, idles a little oddly at ~800rpm, no tappet noise audible inside, pulls quite well - I rarely go past 3k through the gears, as there is no need in normal driving....for me. Low Silicon says the air filters are doing their job, no excess silicon sealer inside. Oil pressure mostly steady at >35psi cruising, >15 idling, although gauge does drop to 0 occasionally without the warning light coming on, so I put that down to a clogged sender. Not using appreciable oil. Generally no point in rebuilding yet, although I have a 3.9 block and heads in hand.