In the Haynes Motor Museum in Somerset, named after the guy who started the famous maintenace manuals, there used to be a 'speedway room', packed with speeedway exhibits. This would have been around 10 years or so back, infuriatingly I can't find my pics right now, but there were race bibs, bikes, pictures, a looping history video, etc. Don't appear to be there anymore on the website the website you need to download the map to view but it was situated in area named 'Motorcycle Mezzanine'. Yes, pretty much right at the back.
https://www.haynesmuseum.org/the-museum/
Time was short so sadly we coudn't hang around, but the girl on reception was amazed when I asked "where the speedway was at ?" as, I didn't have a lot of time. Her eyes almost popped out of her head when I walked past 20mins later saying "that's all I came to see, must dash". I mean who wants to spend hours viewing IOM TT bikes, F1 cars, rally cars, a room full of Ferraris, etc after speedway anyway 😉. Well, I did actually, but oh well.....