I wonder if anyone has any information regarding a text called Maitrāyaṇī Pariśīṣṭa.  I came across a reference to this text in a travel account by a Marathi Brahmin [माझा प्रवास, by विष्णुभटजी गोडसे] around 1857.  In Gwalior, there was a Śāstra discussion about the appropriate month for Upanayana of a Maitrāyaṇī child, and this text was consulted in that discussion.  The account says that the Maitrāyaṇī household in Gwalior followed the traditions of the Gauḍa brahmins.  This interestingly contrasts with the fight of the Maitrāyaṇī community in Maharashtra to be counted among Drāviḍa brahmins, something that I have discussed in an article.