I realize your posting is old, but I recently came into the good luck on tracing my family back to the name Chasse. I am stuck, however, at Firmin Chasse, and am wondering if he is related to your ancestor. I am trying to see if Firmin's father was a Jean-Germaine (I have also seen it as just Germaine). I think your Gemaine would be his son? So if I am right, your Chasse would be his niece?
Thank you for any help you can give!