i agree julian.
i got half a dozen replacement boots from my local factors, in plain bags so i dont know who made them, ive got a good bottom ball joint with a split boot so removed it.
the replacement boots were very slightly shorter in height, but just ok, the bottom seal was not very tight on the seat of the ball joint itself, so maybe a glueing job.
i was kinda hopeing that when its all assembled it will hold itself together, but maybe water will get in.
i think these may be ok to get you through a test etc, but for a long term fix best to try an source the gen mazda ball joint or oem quality part and boot.
like you say earlier this is going to be a bit of a nightmare both for you on a commercial level as you are going to have to charge quite a sum for replaceing a boot, or fit a poor quality part (not really an option). and for us who are going to have to pay lots for the replacement of several rubbers each mot time.

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