Looking at this sourcebook, basing my search on my idea that MMST should probably be in the Halhul district of Judah, I narrowed my guesses for MMST to two sites: Khirbet el-Hubeila (site 835), 31°39’41″N, 35° 6’31″E, with its primary remains being from the Iron IIc and Byzantine periods, with some remains from the Iron IIb, Persian, Hellenistic, and Ottoman periods, and Khirbet abu et-Tuwein (site 830), a single period site with “IA2b fortress and dwelling structures”(!!!). Since Khirbet el-Hubeila was occupied during the Iron IIc, we should expect it to be listed in Joshua 15:59. Khirbet abu et-Tuwein (31°40’6″N, 35° 5’10″E), meanwhile, is the perfect candidate for MMST- a single period site, with a 45×30 m fortress (as from Google Earth) with surrounding “dwelling structures” dating to the Iron IIb (not later, nor earlier!), located in the Halhul district! And on my blog-o-versary, as well!
UPDATE: Apparently, the sourcebook did not tell the whole story. Firstly, the fortress is 31×30 m. Secondly, it was most probably destroyed by Nebuchadnezzar. Thirdly, it was not a single-period site, but was, rather, re-settled in the Persian period. Thirdly, it was not one of a kind, but, rather, there were three other such sites in the vicinity. So, is Khirbet abu et-Tuwein the best candidate for MMST? I’m leaning toward “no”.