Hi, very nice rug. It is a very old Meshed (Mashat) or Mahalat from what I see on the pics. No Sarough for sure. Mesheds of this age are often more worn than other persian rugs, so what you mentioned about areas of lower pile seen well possible. The value of an antique rug is very much related to the over all condition, so it is not possible for me to give you an idea from these pics. The fringes are not original. If you could supply better pictures from the complete rug, and the areas that are worn, would help a lot. Also look out for a signature in the rug. Meshed rugs are usually signed in a cartuche or different color background. The design and color of the rug might speak for the workshops of Kafi, Zaber or possibly Amoghli. I havew added a signature for you to see what it might look like.