Large Vintage Very Early Oak Carved Mirror Painted Black

Large Vintage Very Early Oak Carved Mirror
I thought this was early 20th century due to the plywood backing. However, I then noticed to the two sides there are two disguised dowels. This would suggest this was once part of a huge piece of oak furniture that has been dismantled due to the impractical size. This was quite a common practice. I would therefore date the mirror as mid-19th century or earlier.
The four edges are slightly rough because of its origins and there is some wear to the corner of the edges.
However, the rest is in very good condition with the original painted / patina finish.
There is a small piece of wood missing to the inner aperture, shown.
The glass is bevelled and well preserved. There are some minor patches of spotting which only enhances the vintage experience of the mirror and add to its charm.
Two old brass mirror plates to attach to the wall
Height 65.5 cm
Width 68 cm