Stripped my engine down today, surprisingly easy job really. Hardly a mark on it, no discernible bore wear on 1 and 4, with a teeny tiny bit or wear on 2 and 3 on the bore wall in the centre of the block. Hardly a mark on any crank and piston shells/bearings either. No sludge build up anywhere, a tiny bit of gunk in the sump. For those with 'high mileage' NA engines, in ways there was no need to take this engine to bits, the wear on the engine was so minimal it would likely do the same miles again without worry.
After having it checked over by McKeans in Dumfries they are looking to re-hone the bores, polish the crank surfaces where the bearings sit and fit new piston rings. Total of £300 all in. For those that remember it, if the currently fitted 'gas flowed' head is checked out by McKeans (they have a flow bench) and is good to use, then it'll be mated with my rebuilt bottom end. If not, they'll cut the valves at 3 angles, the valve seats at 2, tidy up the inlet/exhaust ports and skim the head for an additional £200. With the valve work and port tidying they reckon this is likely to flow as well as the head I have already, with the skim giving a nice little performance increase by upping the compression ratio slightly.