10-12-2019, 01:34 PM
I've similarly bought parts from Phil Daintree, but that was many years ago. There's some information here regarding specialloid pistons / rings used in Vincent / HRD motorcycles - a piston ring manufacturing company in New Zealand and a suggestion in the Coventry VOC Parts List that Wellworthy piston rings may fit these motorcycle pistons - worth looking into as regards your Ruby pistons.
https://www.vincentownersclub.co.uk/thre...loid.2760/
http://coventryvoc.co.uk/parts_list_draw...list_e.htm
https://www.vincentownersclub.co.uk/thre...loid.2760/
http://coventryvoc.co.uk/parts_list_draw...list_e.htm