Look for an appropriate hook in the web pages of hardware suppliers. I have seen a hook almost exactly like that, except with about an inch of woodscrew on the long end, which could be cut off. I can't find that in a quick search but this should give you the general idea (this one, you'd have to strip off the plastic coating and cut down)

Repurposing an allen key as suggested in another answer is also possible. However, they are made of hardened tool steel, so you would need a Dremmel and a cutting disk if you needed to cut it down.

Look for an appropriate hook in the web pages of hardware suppliers. I have seen a hook almost exactly like that, except with about an inch of woodscrew on the long end, which could be cut off. I can't find that in a quick search but this should give you the general idea (this one, you'd have to strip off the plastic coating and cut down)

Repurposing an allen key as suggested in another answer is also possible. However, they are made of hardened tool steel, so you would need a Dremmel and a cutting disk if you needed to cut it down.

Functionally if not aesthetically, an 8mm "coach" bolt would work. If it needs a right-angled something on the end, add some bit of metal with an 8mm hole and a nut, locked together with epoxy glue so it can't come loose.