[strictlypersonl]

You should be able to tighten the nut. Even when tightened, it won't be perfectly rigid: there's a bushing inside the "Silent Travel" casting to add some (but not much) flex - and keep the latch assembly "quiet" and rattle-free.
We get our latches in complete (L/R) sets. If you need just the striker, they're available from mossmotors.com. Part number 401-408.