Might try Paul Ackermann at Ackermann Arms:
https://www.ackermannarms.com/
who fabricated a new frizzen spring for my Charleville and seems extremely knowledgeable and competent wrt to the various Charleville repros.
https://www.ackermannarms.com/
who fabricated a new frizzen spring for my Charleville and seems extremely knowledgeable and competent wrt to the various Charleville repros.