Seat rocks forward under braking

[MrChris]

Hi all, going to post this here for more coverage in case anyone has not seen on my reader's ride thread.

My seat has play where the latches for the rails attach underneath. This causes the seat to rock forward slightly under braking and is highly disconcerting.

I've highlighted where these attach via pins in the image below. Are there any tips to stop the play in these pins? I've wondered about circlips, but also wonder if these pins can be squeezed together? Maybe there's something else I'm missing.

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