How to replace the microphone?

My Z3C has been dropped. The rear cover has cracked (looks like a relatively easy job with a bit of time and care) but also the microphone is not working properly. The person on the other end of a call can bearly hear.

Looking through the strip-down, the microphone is not mentioned, but there is an obvious component visible, which is a discrete component at the end, and looking through the other repairs it doesn't seem to be bonded to the screen like the earpiece.

However, I cannot find a microphone as a replacement component on any of the parts websites. On the full-size Z3 it is part of the main flex, but it's not on the Z3C flex.

Any ideas, folks?