What to make of subtle discoloration in this restored piece?

[EdC]

I'm interested in a Wagner square skillet. This one looks very clean. I do notice a little reddish discoloration in here, though... I know when a cast iron gets extreme heat damage, it can get these red/pink discoloration, but it is usually more pronounced than this. But wasn't sure if this is what it would look like if it was covered by a few layers of seasoning?

Thanks?