Rear light assembly

Get a small brass washer, put the spring and the phenol plate back into the bulb holder. strip a bit of the insulation off the wire/ Put through the phenol washer and the brass washer. Splay out the copper strands, and solder. Good as new.

Thanks for the suggestion - I knew someone would have a simple idea that would work

The back plate/reflector is zinc plated i.e. galvanised. Using one of the more abrasive chrome polishes you can get quite a good shine to the reflector areas. Protect with a bit of wax polish. Virtually nil cost except a bit of time, for a noticeable improvement. Next stage, LED or halogen bulbs.

Are LED bulbs widely available and how much are they ? Sounds like a sensible way to go.

There are plenty of LED bulbs around that have additional radial ones to help with this problem. Not a lot of light goes sideways on the Amazon rear lights anyway so I doubt if it would be less with normal but brighter LED replacements. Another link here Halfords, in the chav/bling section or cheap from China via eBay as alternatives.