I have had a look at what handbooks I have in the museums library, the CCUs look very similar having most of the modules with the same number. Sheet two of the CCU drawings, the plugs and sockets on the rear are different, the vidicon one has fewer connectors.
I do not have a drawing for the vidicon PSU, it is in Marconi book T.3975 (hint) but looking at the PSU for the I.O. camera it is mainly the +250volt supply which could be the same, also in the I.O. PSU are the focus, talk-back, and Iris amplifier, these are likely to be missing or different. I have a vague memory that the space is there and they are just not fitted.
So I do think there is a lot of items in common. I can also confirm that the vidicon control panel is the same size and style as the I.O. control panel, but with fewer controls. It is a very attractive panel with black perspex and the lettering is illuminated by bulbs set into the perspex. I do have a control panel for my Mk IV, must do photos of it sometime.
If you are able to do some good high res photos suitable for inclusion in the museum I would be pleased.
Brian
www.tvcameramuseum.org