I have had a reply from Bournemouth Scouts. Provisionally the first date required is 13th November. She has said historic aircraft from WWII and onwards. Actual models on demo and members to give a talk on where, when and why it was built, it's characteristics, engines, problems etc.
I have asked about this certain achievement badge but it may not be the same as the Longham badge so have asked for confirmation either way.
Edit: David T is going to verify the actual badge/s they are attempting to complete.