There have been new developments and I am afraid the prognosis is terminal. After confirming the bad oil reading, I pulled the old filter out of the box and gave it a close inspection under good light. Found chunks and fished them out with a skewer.
Photos below. Several similarly-shaped black pieces, non-ferrous, macro shot shows that they may not be metal.
More alarming is the shiny steel chunk of some cylindrical object, another bit of shrapnel, and a long curly metal shaving, all ferrous.
I don't know what they are but I know I will not run the engine again in this condition.
