Picture of the oil pump failed in the timing case and the wear to the upper big end bearing on Nr.1 piston. The pistons are 40 thou over sized and given the stamp on the block I believe the cylinders were bored out to accomodate. I've ordered a 40 thou oversize KS piston ring to try in the bore and check the ring gap in the bore. As noted before the existing big end bearings are marked with 010 so I'm presuming that these are 10 thou oversized so next step, assuming the rings fit the bore OK, will be to order a set and check the clearance with a bit of plastigauge. I'm presuming that I'll need to hone the bores before rebuilding - something I've never done before so any advice welcome! The Nr. 1 cylinder seems to have very clear hone marks still and no lip at the top or bottom so it seems in pretty good condition.