Sebastopol's not taken yet does date it. The reference to Napoleon is clearly anachonistic, but he was a well known name, so can turn up anywhere post 1795.

The maine law? Possibly a reference to the fishing grounds dispute mentioned above

Re the dance instructions. I can't usefully date it from it's content, but it is of a style I would say is more probably American than British, in the versions above. Virtually all the british dances of this period have a specified number of couples, which this lacks.

Its description as a contra-dance is accurate though. It appears to have a 32 bar dance, in a long line, with a new top couple starting when there is room, as per a modern Orcadian strip the willow