I agree, I noticed the theft in the source code of the two sites. The same thing happenned to cap not too long ago. I would pay a visit to prelinger archive if the site is aged enough. I would also contact the person in charge of this site in a polite manner and explain the sitiuation.
It deemed as a mirrored site the SE will maybe take of the newer site automatically.
I would suggest taking quick action, the options are many. greek39