I realised these scenarios seemed familiar once I started reading them, and I have worked out why: three of these appear in near-identical form in En Garde!, with the only noticeable changes being a) that Seize the Shrine is renamed Occupy, and b) Escort has a randomised time of day rather than having to be at dusk.
As an aside, it seems like versions of Escort and Hold the Bridge were trialled or reworked for the Kenshin Ryu campaign booklet: Scenario 1 is very similar to Escort, and Scenario 5 (if I recall correctly) is a bridge defence.