Those are called shackles. Fabricating one yourself is possible, but probably a waste of time. There's a West Marine
in Taylor that should have about 2000 suitable shackles for you to buy. This place: I94 Marine & Watersports – Family Owned Marine Sales Service in Belleville, Michigan
(closer than Taylor) may also have them. A local hardware
store may have them as well, but you want one made of stainless steel
, which they may not carry. Shackles have pins that close off the opening end. Some are threaded. The pins have to be turned hard to keep them from coming out. Some threaded shackles have captive pins that stay attached to the shackle so they don't get lost
. Other shackles (like the one you pictured) use clevis pins to close the openings. Clevis pins need cotter pins or rings to keep them from falling out. It looks like your shackle lost
its clevis pin. If you can find your old shackle and it isn't too bent out of shape you could keep using it and just get a new clevis and cotter pin. It might save you $1.13 ..