A stock IIC+ doesn't have a DIN socket, as you probably already know. There are just various jacks for switching various functions underneath the chassis, between the preamp tubes and the power tubes.
On the front panel, you have a footswitch jack that toggles between the two channels, but seeing as yours is modded by Jonny, that jack is probably put underneath the chassis as well, since the Volume 1.1 takes its place (if I remember your amp correctly).
There's another jack under there as well, and this one is a stereo (TRS) plug that switches both Reverb and EQ.
If yours has the footswitchable Gain Boost mod as well, that's probably under there as well.
For the CFX4, however, I know that Axess makes DIN to DIN cables (like with a Mark IV), but I'm unsure if they make a DIN-to-several jacks/breakout-type of cable as well. If not, you might just have to use standard jacks from the CFX4 to the IIC+. Just remember to get an insert cable or stereo to dual mono adapter for the connection to the EQ-Rev switching jack.
