There was a Cavalcade of Sport at White City on 20th May 1953 that featured 3 heats of speedway. The format was 2 heats and a final.
Ht1 Aub Lawson, Bill Kitchen, Split Waterman
Ht2 Jack Young, Fred Williams, Jeff Lloyd
Fnl Young, Lawson, Kitchen
Interestingly, the programme states that speedway bikes "would cut up the running track which will be needed this coming saturday". As a result, the riders raced on, wait for it, Vespas. It goes on to say "I don't think that you will be disappointed with their little bit of fun". Speak for yourself - I would have been!
But it does raise the question of was this really speedway at all?