I think there is some possible confusion on the various covers. I'll try to show the differences.
Covers, Waterproof No C1. ZA1076 PC 90674C-191
This was the type used in the Mk1 Carrier. It was attached to the hull side plate between the firing rest and its support. it covered the entire radio area. There were also three sleeves to hold the antenna sections when not being used.
Covers, Waterproof No 1 ZA2952 PC 90816 C
This was used to cover the WS19 and PSU when they were mounted side by side on the Carrier, Set No21. Typically used in armoured vehicles. it just covered the radio and PSU.
Covers, Waterproof No 5 ZA10317 PC 64418 C
Used when the WS19 was mounted on in the ground station roll or in trucks when mounted on the Carriers, Set No23. This covered the entire radio set, PSU, variometer and the switch control box.
