Hand made 18th century French or Swiss Chair

This chair originallyt belonged to my grandmother. The story goes that it was in her house growing up. She was born in 1892 in Basile, Switzerland. Her parents had immigrated there from Alsace Lorraine. They spoke French, my grandmother, growing up in Basile, spoke German.

My great grand father was pipe organ maker. He moved his family to Erie, PA in the early 1900's, before 1910.

The chair has no nails. It is entirely made with slots- the back fits into a slot. Probably once had dowels to hold it, but  they are missing. The legs are held in place by shims driven into the top of each leg. 

I know nothing about it's age at all. Thanks for your help.

Good