Antique Painting With No Signature

So to start the painting is very old and has no signature. I have owned it for 40 years myself and the painting was already extremely old when I came across it. The frame fell apart right when I picked it up. The canvas is very very dark yellow almost turning to a brownish yellow. It has about 8 nails on each side holding the canvas on it has a wooden shims stretching the canvas

 I would like to know anything I can about it like the date it was made generally, The artist who painted it, what style it is, where it comes from  it is 15” Tall and 12” Wide

I tried to explain it the best I could please let me know anything you can thank you very much