Some Westerly specific parts available from these firms:
1 Small run rudder bush fabrication Can do Engineering Abbotskerwell, nr Newton Abbott, South Devon
2 J.E. & J.E. Blount, Precision Engineers, Westfield Works, 23 Old Christchurch Road, Everton, Lymington Hants SO41 0JJ 01590 643286 firstname.lastname@example.org
3 Jock Fraser, J-Tech Developments, No.4 The Square, Southwell Business Park, Portland, Dorset DT5 2NR 01305 823848, 07855 885694 email@example.com CNC production in small batch or one offs of rudder bushes, special bolts and other non stanndard items
4 Richard Ives nr Woodbridge, Suffolk 01728 685636 firstname.lastname@example.org Most bushes from stock or can manufacture others at short notice.
5 f-systems.co.uk are based in Brighouse West Yorkshire, they produce rudder bushes, one-off’s, and custom marine engineering. They normally stock rudder bushes for Konsort/Merlin/Griffon in various materials, and use the drawings published here on the Westerly Owners Association website. They can loan a size test pin for the Konsort/Merlin/Griffon as there are at least two different sizes of these bushes and sometimes even different top and bottom rudder bush sizes. They also make cutlass bearing removal and replacement and prop puller kits. Email: email@example.com website: https://www.ff-systems.co.uk and Westerly parts at https://www.ff-systems.co.uk/westerly_rudder_bushes.html
According to a member the last ones he purchased from Trafalgar and they may still be able to supply. The ones he got had 5086985952 this number on them and he advises this is easy to find on internet. Make sure you check your rudder shaft diameter and ask for stainless steel springs!
Engine Control Panel
Trouts Boatyard Topsham can supply boxes for engine control panels to suit some Beta, Volvo and Yanmar panels
see WOA web site advert here 
Richard Ives can supply Gibb type water/fuel filler caps. See Richard Ives