• Don't worry. Those caps are "not done".
    Screwing in and out increases the risk of damaging threads. Having the dust caps on, it may be too much trouble to check the tightening torque, so you won't.
    You may consider to use such caps for aesthetical reasons, but just very few racers ever rode with them. Just adding weight.

    Anyway, do as you please. Same caps as road cranks FC-740x. That may make the search a bit easier.

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