How many Saṅkarṣa Kāṇḍas are there?

At my new blog (here), you can read about my thesis that there were more than one Saṅkarṣa Kāṇḍa: an ancient, boring and almost-forgotten one and a newer one whose author used the ancient title to gain a position within the Mīmāṃsā-Vedānta śāstra.