Ever Ready "Portable 61" and Vidor "L5039"
See the AD34 or L5050 battery
I do have a photo of the Vidor L5039 (and Drydex/Exide). Also an edited scan (again incorrectly set DPI).
I can upload my Vidor creation from photo and also the Ever Ready version.
The front L5039 front and back are correct (Missing in the photo is "REGD." under the Vidor, now fixed) but the sides are guess work.
Fits in CN420 Regatta and CN379 Riviera. Probably all early Riviera models use it.
This pack was also used in early 2V valve portables before 1939 (Earliest used "wet" and later "gel" Lead Acid LT by 1938, typically 400mA or more LT for 4 valves.
Inner tray is pizza box card and outer tray is A2 "Art" folder cut up. A great source of cheap really heavy card plain blue for only €3 per folder (A1+ when opened?).
Inkjet printing on 90gm paper and Pritt stick.
10 x AA holders and there will be a block of wood running length of box with two "coffee tin" sockets for the wander plugs. A fuse is recommended!
Zinc Carbon AA about 100 hrs HT and Alkaline AA about 250 hours+ HT (similar life to original 60 x B cells = U10). So under 8 pence an hour running cost.