Hi Jarrad, I have finally found some information on Scott Bonnar chains that I have been searching for, for ages.
Primary chain (engine shaft to cutter) : 3/8" pitch Cutter to Roller Clutch: 1/2" pitch Clutch to Rear Roller: 1/2" Pitch. Some members might not be aware that there is a difference between the primary and the other chains.
Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member. Kindest Regards, Darryl