ECW Skirmish rules suggestions

[Radar]

For small unit skirmish File Leader, for more details see https://www.keepyourpowderdry.co.uk/2023/03/file-leader.html
For individual figure skirmish Once Upon A Time In The West Country, for more details see https://www.keepyourpowderdry.co.uk/2022/09/once-upon-time-in-west-country.html

Old, but still very good, and still available new (Caliver, and I guess OMM)

[Mammoth miniatures]

Is there any specific reason that the skirmish ruleset MUST be civil war themed? Weapon wise it's hardly a stand out conflict - muskets, pistols, swords, pikes etc.

Most man on man skirmish rule systems will do the job. . Really you could just pick your favourite pre-modern skirmish system and use that.

Test of honour would probably work really well of you just renamed the units.  I can see mordheim working quite well if you simply stick to empire Vs empire warbands.
Blood and plunder could be a pricey way to do it if you just ignore the boats.

[recceboss]

Thank you all for the replies & excellent suggestions!