Also, these conversions should be handy for any small-scale skirmish (like Witchfinder General) or tabletop roleplaying set in the era and region.
First are the Hussars, converted from spare Uruk-Hai in a manner inspired by mrtn's work here. The armor doesn't translate perfectly, but it's in the same ballpark. The pistol and gun are Warlord, the sword is Perry ACW.
Next are Pancerni, from Gripping Beast plastic Vikings. Just a more completed version of what I've already posted.
Here are some Reiters, a mix of the Firelocks kit and the Cavalry kit from the same era, and also the occasional WGF WSS arm. Also greenstuff for the boot tops. The one with the feathers is a metal purpose-built dismounted ECW cavalryman, also from Warlord.
The last three are footsloggers, with full-sized firelock muskets instead of the cut-down carbines their compatriots are carrying.