Who Built the Kosel Hama'aravi?

In a previous post, I wrote that the Migrash of Har Habayis went until the western wall of the present day temple mount, the Kosel Hama'aravi. However, there is a problem with saying that, because the stones of the Kosel are all Herodian-style stones (stones with margins and smooth bosses), and there are no seams to mark the beginning of Hurdus's extension, so it can't be from the time of Shlomo Hamelech.
    
    In order to solve this problem, I will point out something strange about the Kosel. The southern wall of the present day Har Habayis is 2.25 meters (27.7 ft.) thick (The Quest, page 69). The eastern wall is 2.88 meters (9 ft. 6 in.) thick (Survey of Western Palestine-Jerusalem, page 238). The western wall, however, is almost double that, it is 4.60 meters (15 ft.) thick! (The Quest, pages 25, 29). 
     
   It seems that the reason for this is that originally the Kosel was built by Shlomo Hamelech. Hurdus, when he rebuilt the Beis Hamikdash, added another wall right in front of Shlomo's, hiding Shlomo's wall. For this reason, the Kosel is almost double as thick as the other walls, because it is really two walls. (A possible reason why Hurdus did this is because this wall was by one of the main streets of Yerushalayim, so he wanted it to look smooth.) For this reason, we daven by this part of the Kosel, and not opposite the Kodesh Hakodoshim, because right here the wall is partly from the first Beis Hamikdash.