1760or1895

I need some help! I have 6 dining room chairs made of Cuban mahogany. The reason I believe they are Cuban mahogany is I have sanded the bottom of one of the chair legs to 400 grit. I also have sanded a piece of Cuban mahongany that a forester gave me that was planted in Hawaii in the 1800s where the old train station was . Then I compared the wood cell structure and they were the same. From research on the internet someone said that period chairs have three pieces that make up the back rest and chairs from 1890 Thur 1910 have two pieces that make up the back rest. My chairs do have three pieces. Each chair has some deep purple wood and some lighter wood. It seems that whoever made them did this for contrast. The chairs are all slightly different heights different widths the shells range from 3 1/4 to 4 1/4 they all have ball and claw feet and they are the same with slight differences. The chairs look the same but when you look closely you see that they are all different. Do you think I have period chairs from 1760 or chairs from 1890to 1910? I appreciate any feedback thank you Larry. The chairs are waiting to receive a coat of lacquer they were painted