Didn’t want to fork out 50 quid for a servo buddy on fleabay so I found two DIY threads on some ZX10R forums here and here.
Ordered the few components from Maplins and here’s a few pics (I went with the second thread linked above as there was some talk of needing to discharge the cap with the simpler circuit)

When I got the bike the previous owner had removed the cables from the servo motor to the exhaust valve. With the motor still in place the ecu doesn’t throw a fault code (which displays on the FI light on the dash) All this gizmo does is then allow you to remove the motor to free up some space (I want to throw an alarm in there). It tricks the ecu into thinking the motor is there.

Remove this to free up some space…

Ok it doesn’t look great but it does the job…

But that’s all hidden away…(Cut off the connections going in the motor to repurpose them)