M_Boats: Old Rope

Need to replace all the rotted rope on what is becoming my M17. (By “all the rotted rope” I mean _all_ the rope.) The pieces that are left measure 5/16”. That looks right for the halyards and incidentals, but the sheet blocks and cleats look like they were intended for something larger. What is (are) the usual sizes? About the only piece that isn’t coming apart is the centerboard pendant. It’s tempting to leave it alone as I don’t really have a plan for getting at the centerboard.