There is a very thorough list on https://benchpeg.com/resources/galleries-and-boutiques

Places near Yardley Hastings:
Uppingham

https://madegallery.co.uk

Olney

http://www.boo.uk.com

Cambridge

https://www.primaveragallery.co.uk

Exhibitions and fairs

London

Homepage

https://www.vam.ac.uk/collections/jewellery