Sorry for the lack of photos and thanks for the replies so far. I'll work in trying to get some pics uploaded. I have done a bit more reading up and also had a good look at what is on the bike.
So.... There is a flat, solid plate bolted over where you would normally expect to see the exup cover. The exup cables have not been removed from the bike. The ends of the exup cables that have been cable tied together and are hanging redundantly the above the plate.
Having done another 80 miles on it today I have got a bit more familiar with how it rides. The top end is still how I imagined it would be; a smooth rush of power, that pulls cleanly from 6rpm. The low pulls smoothly through the revs when pulling away from standstill or accelerating from low rpm, the engine doesn't significantly bog down. However, there is quite a difference between the power available below and above 6rpm.
The main issue im noticing is when holding a steady throttle anywhere between just under 3rpm and up to 4rpm. In this rpm range the bike kind of chugs and sounds like it is coughing slightly. Not enough to cause panic - but it sounds different to the smoothness of the engine when at tick over or at higher revs. At these moments it gives the same sensation as riding a bike with an extremely slack chain - a repeating pulsing motion of being surged forward slightly fraction and then held back while on constant throttle. (Chain and sprockets are fine by the way)
So.....
I suspect the exup has been removed and not replaced. (The bike is 2002 with only 9k miles - probably been sat for long periods during which the exup could have seized up).
If a mechanic removed the valve for modding purposes, would they remove the cables too? Not just the valve itself.
Do these engines that have had a dyno jet kit fitted run this way? more specifically, do dyno jetted bikes run like **** at low revs but then hit 6rpm and then fly!?
My lack of experience on litre bikes is holding me back here. It still feels beefy and a step up in power compared to the cbr600f, but I know something isn't right. If anyone who can prove insurance and leave there own bike as deposit wants to meet and take it for a spin in Hertfordshire, let me know!