This is the original image, it needed significant color adjustment. But the mat sleeve was mostly ok, so we had to isolate just the tintype portion.
The Elements file has several layers. 1) Just the tintype image, 2) just the frame, 3) and three different adjustment layers. The tintype was cut out using the Polygonal Lasso tool and placed on a separate layer.
Can you figure out why there are two Brightness/Contrast layers? We reached the maximum amount of brightness in one before it was where we wanted to be. So we just added a second one.