OK results are in.....

Had it done at Scooby Clinic and the way it was explained to me was that the machine has a gauge with red, orange and green on it.

Came out with 2 cylinders great, right at the top of the green section. 1 was around the middle of green, the last was just into orange. So that explains my oil usage.

No leak from the exhaust so the exhaust valves are all good.

It has been explained to me that while it's not amazing, it's also not so bad and it will map and be fine if looked after etc. but I may find the figures will be a bit down on what they would be on a completely mint engine.

I'm slightly wary of carrying on with any tuning despite all that, so I really need to think about it going forward. I'll certainly be very vigilant with oil changes.