Just for my own notes, or anyone else that reads this, I've tested the inputs and outputs of the reverb board, of which the pin outs are;
This appears to be the same reverb daughter board as used in the Orange CR60 and CR120. The board is getting the 5v it needs so I've poked around with an improvised audio probe, I've found the reverb board is getting audio on it's Input pin, there is also audio output from the reverb board on Out1 and Out2. My audio probe isn't amplified so I can't quite tell if the Output is reverbed, but it's a start. The two OUT signals appear to join up to one signal and continue over to the opamp U3, pin 3, (1IN+). The reverb output is much lower than the input, but I'm not sure if that's expected or not.
That's as far as I've got