No apologies necessary Mart - you've been really helpful - thank you.
I stripped the bottom end of the engine out yesterday - things happen for a reason don't they? Finding that the mating face of the block was not flat, meant getting the block ready for the machine shop to plane the surface flat.
In doing that, I found that Nos 1 and 3 pistons had broken compression rings - clean break in both cases, no bore damage. Also that No4 big end shell bearings were both deeply scored, probably by a bit of grit. The crank journal will hopefully polish ok within tolerance. All other bearings and journals are fine.
Waiting now on the word - whether the crank will need a re-grind and whether the block is cracked. I don't believe it is and if not, it will be chemically cleaned, the bores honed and the mating face planed. I've asked that they note how much they remove to get it flat.
Another parts spend beckons now for a full set of standard pistons rings and +20 big end bearings, plus various gaskets, water hoses etc etc - the expenditure debit column knows no end with this car. Bulletin ends - for now - there will be more!
Thank you again to all contributors for your help - much appreciated fellas.
If you are getting the block face planed don't forget to give them the timing cover to do at the same time - like I did!