Hi Nigel,
I don’t know what the Slough wheel looks like under plastic coating. My 1955 Light 15 came with a pre-war 3 spoke wheel with the same problem of peeling plastic.
I stripped it all off and found that the 3 spokes were cast aluminium.
I de-rusted the rim, polished the aluminium and sprayed the rim brown.
Not original but I think it looks pretty good, and a lot less than £350 🙂

After

Before
Roger