Kalman Borkum

For a long time I am trying to find more details and connection to Kalman Borkum - that lived and was one of the community leaders in Courland, Lithuania. so far I failed and I hope that maybe one of you will have some information or direction.

I have added Kalman to GENI as independent tree - Kalman Borkum with Kalman is actually myself with the following details:
Court Jew of Duke Peter Biron of Courland; born in the middle of the eighteenth century; died at Mitau in 1828, on the same day that his brother Simson died. Owing to the influence of the Borkum brothers, Jews were permitted to settle permanently in Mitau, to organize themselves into a community, and to engage in trade and handicrafts within the dukedom of Courland. In 1775 the Jews of Mitau were permitted to send their children to a gymnasium called the Academic High School. In 1784_Kalman Borkum erected, at his own expense, a synagogue and all the other buildings necessary for the Jewish community. See Courland; Mitau.

The reason I am looking for this is because my great grandmother from my father side come from Borkum family.
I have added all I found to GENI - the root of the tree is currently -Moshe (Movsha) Borkum - Movsha Borkum

If you have any hint for e I will be really thankful.
Omri