jib halyard - on my 18's the block is at the end of the wire halyard. You should be using a rope halyard thru that block to raise the jib. Purchased a new one recently that didn't come with the block. I am running the rope thru the eye at the end, works fine. The stock block doesn't have a removable sheeve. On the swivel- they do get flat spots and corrosion. You can clean and lube to get more time out of it. I have installed a swivel above and below the turn block on the forestay, its not necessary but if one sticks the other won't. It adds 1" to the overall forestay lenght and weight is minimal. I also use the jib halyard with sister clips spliced into it, I think that item is more than worth its cost.