I suggest you to look in google book for the following :
Deutschbalten, Weimarer Republik und Drittes Reich, Volume 1 by Michael Garleff
you will find an extensive and detailled bio of this "deutschbalten" son of an estate owner.
Some datas pic up : He led Woiseck then Eigstfer familly estates until 1939. He was a former Rittmeister (1917) of the latvian army and was CoS Baltenregiment from 1918 to 1920.
Soon involved in NS activities (1927). He wrote the rules of the "baltischen NS Bewegung Estland" in 1933. He led the Volksnationalen Vereinigung (VNV) from 1938.
On 1939 he join SA and moved to Posen on 12/39 he was with EWZ stelle Nordost. On august 1940 SA-Hstuf Stab Gruppe Warthe. 1/10/1940 joined NSDAP.