Macgregor 22 keel cable sizing

[Dougiestyle]

Hi all Dougie here,
I recently purchased a 1981 Macgregor 22, which is in pretty good shape. I was told it has not seen any water in about 15 years. I dont see any rust on the keel, and the bottom appears to be in pristine shape, even where the keel sits.
I was putting a new brake winch on, and the cable is old with some worn spots on the cable, along with 2 broken strands. So I have decided to replace the cable The cable appears to be an 1/8" cable. What size is the recommended size for replacement? 500 pound keel. Would 3/16" be a better choice? I can make my own cable with nicopress connector.
Is there any drawings or something of the sorts for the Mac 22?
Thanks
Doug

[sporgo]

I used 3/16 stainless and nicopress fittings. Had to order the fittings online as all the local suppliers had was aluminum.