Hi,
The 'scars' on the frame are pretty normal for a gun that sees regular use. The same goes for the toggle ramps. Repeated contact with the toggle knobs will eventually wear off the blue.
In my opinion, this gun has been well and thoroughly used, possibly not with the best ammunition for it, causing the defect in the toggle train.
But then again, we have to remember these guns are getting 'really' old and defects will develop, even when using normal ammunition.
I would not use that cracked middle link for anything other than display purposes. I certainly wouldn't want to shoot it in this condition, or with a welded up middle link. Get a replacement link.
Compared to the frame of my shooter:
