I have the MK II s-cross cb, and my display if different again.
Mine cannot fit a throttle or have its speed changed either.
You say the controller and display needs to be changed. Is it difficult, and do you have any recommendations
Hi- it's not particularly difficult (a bit fiddly perhaps), but if you're ok with wiring the controller up, (which will involve either soldering, or using connectors), then it's not difficult. Probably the most challenging bit was getting the new controller and the wiring back into the cavity in the frame, as space is limited, but it will fit! I also fitted a different PAS sensor, as it was easier than trying to fathom out the wiring on the existing Oxygen one! I bought a more expensive (colour) display too, which wasn't really necessary, so a cheaper one would work just as well. So the parts needed were a controller, a display, a PAS sensor, and a twist grip throttle (I tried a thumb one, but there's limited space for it, so changed it to the twist grip.
The whole lot cost about £100, and came from TopBikeKit (based in Hong Kong), who were very helpful + knowledgeable, and my order arrived in less than a week. If you need any more info, just let me know, cheers, Mick
ps The speed is now easy to change, and my bike is now quite happy doing around 20/21 mph (even without pedalling), which I think is fast enough for a bike!