I've bought my C&C Mk2 1987 this spring through a previous owner that didn't sailed the boat. I've seen no where the details for the backstay adjuster, it uses a pair of block on a split backstay. The main problem is that I see no evident attachment points for this block and pulley system.
I've pulled the following image from a listing in Yachtworld where we see the general location of the system but the attachment point is not clear. There seem to be 2 attachments points pretty much in line with the split backstays.
I've also included a photo of the back of my boat. Would the system attach itself just below the turnbuckle?