Somwhow, somewhere today my Xperia 10 iii lost it’s volume buttons, there is just a hole in the case now. Does anyone know where I can find a replacement part?
Edit: managed to find the button, but one of the retaining tabs is broken so it will no longer stay in place.
I’d suggest searching for a case that holds the button in place (maybe with some help of glue or double sided tape and passes through the mechanical action?
Is it this one ?
I had the same issue last year and ordered from the above site’s predecessor (it relinks) but never got the piece nor my money back, so I really do not know can you trust these people? Your call.
True sailor way, I just cut from a large, thick but flexible elastic band a strip and stuffed it in. Survived 12 months of salty Atlantic cruising and still going strong, so why bother… 
Just search on Aliexpress.
Thanks for all the suggestions. I’ve ordered a TPU case that will hopefully keep the volume button in place.