Well after all that, we didn't
.
Rosie threw a hissy fit (must be because I washed her again) lost all oil pressure (didn't believe the gauge but that's a long story) and ran a big end on the A120. Ignominious wait for the AA and a tow home one one of their new fangled car trailers that pop out of a the back of a Virago/Renault/Nissan van.
Tim