In the book 'A World Apart: A Memoir of Jewish Galicia' by Joseph Margoshes, on p180 there is an five page Margoshes Family Genealogy prepared by Rabbi Eliezer Lippa Gartenhoyz from Margoshes family records..
On the section about R' Ephraim Fischel it is said:
"1) Our ancestor, the well known rabbi and benefactor, his Excellency [Gaon] Rabbi Joseph Margoshes, may his memory be a blessing, is buried with honor in the holy community of Lvov, near the grave of his father, the well known rabbi, Eliezer Magoshes, may his memory be a blessing, a trustee of the [Council of] Four Lands. Written on the gravestone of our ancestor, Rabbi Joseph Margoshes, is the following:
Grandson of our Rabbi Ephraim FIshl, president [of the Council] of Four Lands and president of [the supporters of] Eretz Yisroel.
The grave of our ancestor R. Fishl is by the head [of the grave] of our ancestor, Rabbi Joseph Margoshes."
This account of various prominent gravestones in Lvov suggest to me that a new branch from Rabbi Ephraim Fischel HaCohen, [of Lvov] ABD Lukow is warranted. This branch would have an unnamed daughter bca 1610 marrying a R' Eliezer Margoshes, Trustee of Council of Four Lands, bca 1610, and they would have a son named Yosef Margoshes bca 1640.
I am sure that there is a genealogy from Joseph Margoshes forward into the present but I am not aware of its location on GENI and I no longer have the above book in my possession. If someone is able to connect Joseph Margoshes to a further tree on GENI or elsewhere I would appreciate knowing about it.
Thanks.