> they discover a battered Union Jack flag on the surface and a handwritten note, dated some 65 years earlier, claiming the moon on behalf of Queen Victoria. Stranger still, the note is written on the back of a court summons for one Katherine Callender from the village of Dymchurch in England.
This reads like the beginning of a Doctor Who episode.
Nigel Kneale, who wrote the screenplay, famously wrote Quatermass, so you're in the right area - that was a big influence on early Who. Kneale hated the idea of Doctor Who though, and refused to write for it - he said "It sounded a terrible idea and I still think it was." (specifically, he hated that it was designed to frighten small children)
This reads like the beginning of a Doctor Who episode.