The only bits I have come across are in Ospre's New Vanguard-104
Cromwell Cruiser Tank 1942-50
The Comet gets a brief mention here and there and there is one picture of
the Comet "ST Andrew"
A liitle paragraph says Quote
There is no hard evidence of the exsistence of Command and Control Comets before the end of the war,although regimental commanders
certainly used Comets and surviving post war documents include illustrations to show the turret interior fittings of an official command
and control Comet.
In the bit of info about the Photo of the Comet ST Andrew,It repeats
Although Official Command and control versions of Comet were introdused
after the war,there is no record of them earlier.
Thats about all it says about the A34 Comet so dont spend the Â£9.00 + on
it,have a read of it in the book shop
I couldnt see any mention in the Armor Photogallery book.