This is similar to the Z50 setup, only that one had had a 3-hole/triangular lockplate...to match the Z50s 3-hole sprocket mounting. That's why I asked what bike/model you have. Only need to bend one "ear" per bolt head. You should have a pair of these, for the 4-bolt setup. FWIW, I'm not a fan of rigid-mount wheel sprockets, either. Honda used rubber dampers on just about every machine over 49cc and for good reason.
Here's a source for an OER swingarm bolt. Unless you really know your way around fasteners, it's just easier to go with the Honda part, failsafe too.