I have some further information which might help.
Examining again the Power Supply Unit (PSU) in a strong light I realized that the Raycom Ltd label was stuck over another one. This label says Academy-CB. I reckon that Raycom sold this Academy-CB product model CB-524 under its own name. I found a photo on ebay in the completed listings which is identical to the one I have except for the Raycom sticker:
https://www.ebay.co.uk/itm/Academy-C...p2047675.l2557
If Raycom sold Citizens Band Radio ( CB ) equipment in the 1980s then this product would make sense as a PSU for people who used CB Radios at home - as distinct from the 12 Volt powered car usage.