Trikarmi brahmins?

[Madhav Deshpande]

Dear Colleagues,
        I am reading a Sanskrit text that deals with the question of
whether Vaishyas are eligible for Vedic rituals in the present day.  The
first 2 pages of this printed work are missing, and hence I do not know
the title of this work.  However, it looks like a Nir.naya document
composed by some authority from the Shankar tradition.  It is published
with a Marathi translation, and dated Shaka era 1847.
        One of the discussions refers to Trikarmi brahmins, who are
half-brahmins.  They can learn the Vedas, perform rites for themselves,
and give gifts, but they are not permitted to teach the Vedas, perform
rites for others, and receive gifts.
        Among such Trikarmi brahmins, the text mentions the following
names:
        Koppalu (= Koppal in Karnataka?)
        Caturvi.mzati
        Sakalatrapuravaasin
        Zi.syavarga

        Such a belief is commonly held about the Gaud Sarasvat brahmins by
other brahmins of Maharashtra (Citpaavan, Dezastha etc), but I have no
idea about these other groups.  Any information regarding these names and
communities is appreciated.  Best,
                                        Madhav Deshpande