James when you had the head off did you test the bores for wear or worn rings and have you done a compression test? I'm sure you know a lot more about these things than me but just thought that these things would be obvious to see if as bad as you say it is :-/.
The only conclusive thing would be a leak-down test.
I compression tested it before removing the head, but when there is oil floating about, it can play with the readings a bit
A compression test will also tell you very little when it's burning oil, EG, it runs on 4, and has good compression on 4 - however that doesn't mean the oil rings aren't knackered, even if the two compression rings on each piston are OK....
Beginning to wish I'd re-ringed it while the head was off, but I Was so sure looking at the valve seats etc that it was stem seals, they were covered in oil
