It seems very difficult to find anything on the type of radar used on the WW2 Vosper, possibly due to the secrecy that would have surrounded it.
The British were not nearly as good at photographing military equipment as the US! Or maybe more heavily censored?
I have recently purchased a couple of photo's of P.1023 and P.1033 which were, post war renumbered MTB's of the 73' type II's with some armaments removed. I have scanned the radar heads of these photo's at high resolution and published them below.
I may be totally incorrect and the type 268 radar may not be exactly the type of radar head on MTB523 and I would be glad to receive any feedback!
This is a high resolution image of the radar head of P.1033.
Note that the "bongo drum" basket antenna is circular when viewed from above or below and there is an extra dipole antenna attached to the end of the cross beam that was not fitted to MTB523. It also looks like it's well insulated from the cross beam so may have been quite high voltage!
This is a high resolution image of the radar head of P.1023
This is a good example of the mast top from below and a great view of the "bongo drum" basket antenna. This is how the bongo drum antenna was fitted on MTB523.
A close up view of the type 268 radar head.
This is Canadian equipment but the mast head looks identical. The power supply looks like a motor/generator, which was a good way to stabilise the voltage in the days before power electronics.
This is a picture of a plan position indicator from the era that seems very similar to what is shown in front of the wheel in the bridge on MTB523.