1968 Widecase 350 Scrambler

I am in the process of rebuilding a 1968 350cc Widecase Scrambler fitted with 35mm Marzocchi Forks and since the boxes of bits didn’t include springs I am looking for a pair which, I believe are 460mm Long X 23.5mm O/D. If anyone knows the whereabouts of such springs or even the measured distance between coils/spring rating I would be grateful.