Strange Aeons is a commerical rules set, but if you already own it, you may be interested in these free modifications for playing in an 18th Century setting.
rules
A Splendid Victory ECW Rules
A Splendid Victory is a set of free wargames rules for the English Civil War. They’re designed for 28mm figures, but the basing system is flexible.
Quick Play Low Intensity Warfare Campaign Rules
Quick Play Low Intensity is a set of free wargames rules for playing campaigns set in Vietnam or similar conflicts.
Richard Bradley’s Samurai Skirmish Rules
The prolific Richard Bradley has a set of free wargames rules for samurai skirmishes.
Richard Bradley’s Seven Years War Rules
Richard Bradley’s Seven Years War rules are designed for 15mm figures on a 40mm frontage.