I flew into a PFA rally some years ago and was amazed at the contents of the hangars (all open, no charge IIRC). Couldn't the Science Museum organise some volunteers to run weekend open days? If I lived near I'd be up for it!
At an Open Day about 5 years ago, predictably, the only aircraft hangar open was the main one with the Connie. But there was also access to one of the storage hangars, with a superb collection of British jet engines from the 1940s onwards.