That's one of them. There are two brackets for the guard: one with two holes for the left side of the guard and one with one hole for the right side of the guard (which is what you found). You have to turn and maybe bend the bracket some to make it work for the guard, it all depends on how you have the guard positioned on the bike. Here's what the original Cat chain guard brackets look like.
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You can easily get another one remade if you can't find the left side two-hole one because the user I mentioned above has been repopping them.