I just received further updates from AV Engineering.
Upon disassembly of the engine parts they encountered a problem when attempting to remove the worn bearings from the the front cover of the bottom half of the block, see photos below:
The bearings were corroded so hard into that cover that it actually cracked on removal despite AV trying to heat it up in order to remove it:
Furthermore, one of the oil pipes also cracked on removal due to corrosion:
These are serious issues as the cracked cover can only be purchased as part of buying a new sump which comes in at a ridiculous cost of thousands and the little cracked pipe replacement itself is £350 + VAT!
However, once again, the team at AV Engineering have stepped up to the plate and come up with a cost effective solution. They have managed to source both items from a scrapped 360 engine for the princely sum of £250!
Obviously I am extremely grateful to them for taking the time to source these things and more importantly at such a low cost. Hats off to these guys - not a lot of people would have gone to the trouble they are doing for me, very impressive indeed.