Gents,
The Working and Fitting Instructions for W.S. No. 38 Mk II or II* in Churchill Tanks can be found here:
http://www.vmarsmanuals.co.uk/archiv...chill_Tank.pdf
On page 18 you can observe the nomenclature for 2 different "Carriers":
"ZA 16870 Wireless Sets No. 38 Mk II or II* Carriers No. 4" is used in Churchill
III and IV.
"ZA 17203 Wireless Sets No. 38 Mk II Carriers No. 5" is used in Churchill I and II.
So the Carrier under discussion is not for a Churchill but it may house a No. 38 set in a different vehicle.
Colin