Shims to fix old chair

I have some old chairs that I have re-glued over time but eventually they keep falling apart.
A friend of mine gave me this little gizmo. These are essentially metal shims which are dented (a bit like fish hooks). Problem is, he only has a few left and he forgets where he bought them.
Anybody here has a clue where I can find these (online)?
Here are some photos, also showing how they are used.

Hi Mate.
I would not worry about those shims.
Use, thickened Epoxy glue instead.
Available from any marine dealer.
Paul

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