Yakker
Have I seen that!!
Some years back an owner asked us to do the annual check on his aircraft, the last MO had not done any AD's or SB's four of the AD's involved control or major structual inspections, all items that could end your life very quickly if left undone.
The whole thing was summed up at the end of the inspection when the oil pressue failed to get into the green arc.
The owner said to "leave it" as it had been like it for years! I was not about to release this to service with a potental oil pressue problem so we investigated it.
It turned out that the last MO had fitted the wrong PX sender, so this had to be changed, they had also (no doubt during the investigation of the snag) lost the nuts from the back of the gauge and had fitted american nuts on a metric thread............... the result of this was the gauge had to be replaced as well due to the damage done to the gauge. Quite early in the investigation we found that the engine oil pressue was in fact running over pressure, no doubt the oil PX had been set at a high pressure in an attempt to cover up the indication issues.
The net result is that for the first time in years the owner was flying an airworthy aircraft, however he was very unhappy with the price and refused to pay for what he considered to be unnessesary work, eventualy a settlement was reached and the aircraft went back to the former MO.
I have little doubt that the owner is now flying around and very happy in is cheaply under maintaned death trap.