Re: Centerboard cable/rope?
I switched to rope on my older O'day, and it held up well.
Attached with a narrow shackle from an O'day parts source. The only issue I had was the drum on the trunk that held the rope when the CB was up was sized for cable, and getting all that rope to fit was a challenge. Whereas the cable had some extra length the rope needed to be the exact length needed, with no extra. Your setup would most likely be different though.
'72 Catalina 27 Tall Rig #519