Right so I've probably jumped the gun alittle(no surprise there)
Been to a different shop, very blunt this guy(just what I need and like)
He said that the scores are dirt, he was very sure when he said "THATS DIRT!"
He said that the block wash they did was "horrendous" and that no matter how clean I was some **** was going to get in soon as I rotate the block.
We checked the clearance(although only with a feeler gauge) but he said "no that's about 0035" so an apology to dartford rebore for that! Not so about the block wash though.....
Pistons he said are reusable, lightly 600grit paper on them but VERY lightly.
He said the scores will come out with a hone so he's going to hone it.
Then wash the block in the parts washer for as long as it takes then in the hot tank for a further 8 hours, should come back clean as a whistle.
My airfilter isn't great quality either, I can see straight through some sections of it, probably not to blame but worth changing for a quality filter anyway.
So parts list is
New rings
Probably new bearings although mine look good.
New airfilter
Headgasket
Run in oil and I should be good to go again. If it was my fault dirt got in then that's also a valuable lesson learnt to try and be much cleaner while building it again, pretty sure it wasn't me but...