found out after taking apart the front brake caliper that a lot of parts are now no longer available. The piston has rust bubbles on its surface and the barrell has a kind of alloy oxide coating thats causing drag on the piston as it moves . The brake connecting rods you cannot get and I broke off the bolt in one.
Managed to salvage the connecting rod but am now trying to get the piston and barrel of the caliper polished professionally.
The guy has guaranteed his work and can remove the rust without affecting the diameter of the piston. Its the piston seal clearence thats critical
I will let you know how it goes once installed as this is something these older goldies suffer from ( Lack of parts!) If all else fails I can get a piston fabricated for around £20.00. Mother Honda wants at least £40.00 for its part.