Kennet Ryland,
https://www.sanshin.co.uk
Distributor of all sorts of boats bits but especially for Goiot spares in the UK. He was very helpful in sourcing new stanchion feet (now obsolete) for a 36C back in 2020.
Also Eagle windows as above who are now the sole suppliers of replacement lenses for the one off size Lewmar opening portlights found on many Dufours.
Otherwise Ocean Chandlery in Emsworth who stock a wide range of Lewmar bits especially hatches either whole or most of the bits such as hinges, handles etc.
https://www.oceanchandlery.com