20-21 Visual Arts Centre in Scunthorpe are advertising:
Art in Miniature 15 July - 28 October
The first major exhibition of Fantasy Miniatures in a UK public art gallery, bringing together leading UK modellers and makers.
More details and artists are listed here
https://www.2021visualartscentre.co.uk/art-in-miniature/I think they may have forgotten the Ray Harryhausen collection in the National Science and Media Museum in Bradford though 'technically' that had Sci-Fi in it as well and its currently closed for a rebuild...
If you do go, parking in Scunthorpe is currently free for the first two hours weekdays (free all Sat / Sun) or if you park in the multi-storey by the Vue Cinema on the map and walk (3 mins) it's free Weekdays PM - you need a ticket for all free periods.