From memory, believe that the OEM reef line jam cleats at the goose neck are the same as my 1980-82 Cherubini Hunter 36.
Buying the boat in 2007, I never liked the stock reefing setup at the goose neck. So I modified as described and pictured below ... which had the benefit of doing away with the jam cleats. For me, setting the reef was ok, but the springs would pull the cleat into locking position even when the line was slack. The reefing line would not run back through the boom when shaking out the reef. And also the line would not stay over the ridiculously small OEM sheave. Once off the sheave, the line would not feed well into the small opening at the goose neck.
The attached pictures show the original design (included so you can compare if it is the same as yours) and the modification I made. The large fender washer prevents the lines from jumping off the small sheaves. From inside the boom, the lines run down to blocks at the base of the mast, then back up to securing cleats on the mast. Pulling up on the lines before cleating allows for pretty good body tensioning position to get the clew close to the boom.
Subsequently I've replaced the fender washers with anodized aluminum cheeks salvaged from a nautical flea market block I purchased. The cheeks are larger in diameter than the fender washers and work better. The setup performs great for me. Items needed are: A 3/8" SS bolt (or maybe it was 5/16" ?) of the right length and a couple of washers and nuts. An old block for the salvaged checks. Couple of blocks at the mast base. I already had several cleats mounted on the mast.
