Estate Find Mystery DO...what is it?? Comments Please!!!

I found this 5 QT Dutch Oven at a local estate sale and could not walk on past her. The price was right!!
But what is it? Griswold??
Who is the manufacturer?
the marking are very basic.
On the bottom:
5 QT
B
on the inside of the lid:
8
Self Basting Lid
1288
Looks old and well made and used often.
Need to know how to best to get rid of the rust on the underside of the lid??
Here are the pictures!!
Shady











But what is it? Griswold??
Who is the manufacturer?

the marking are very basic.

On the bottom:
5 QT
B
on the inside of the lid:
8
Self Basting Lid
1288
Looks old and well made and used often.


Need to know how to best to get rid of the rust on the underside of the lid??


Here are the pictures!!





Shady