For a fellow BC-12D restorer here in the UK, I recently did some research on the trim system cable and cable tension spring that I sourced in 2004 for my own rebuild back then.
Back then I had a batch of trim cable tension springs made; I've only one left now, so I made some measurements in case anyone else needs to make some under "Owner Produced Parts" rules; see attached image.
The trim cable I used was 1.5mm (1/16") diameter 6X7 (or 7X7, depending upon your terminology). Similar wire rope is readily available from eBay (for example here:https://www.ebay.co.uk/itm/283886720022
Here's the trim spring:
Back then I had a batch of trim cable tension springs made; I've only one left now, so I made some measurements in case anyone else needs to make some under "Owner Produced Parts" rules; see attached image.
The trim cable I used was 1.5mm (1/16") diameter 6X7 (or 7X7, depending upon your terminology). Similar wire rope is readily available from eBay (for example here:https://www.ebay.co.uk/itm/283886720022
Here's the trim spring: