As stated in the logo, E.P.S.K. is an abbreviation of Edgren, Palmgren, Sjölin and Kroon. Edgren is on my grandfather's side, Palmgren on my grandmother's side, Sjölin on my grandfather's side, and Kroon on my grandmother's side.
Edgren and Palmgren are from Munkfors and Ransäter in Värmland, Sjölin is from Helsingborg in Skåne, and Kroon is from Järbo in Älvsborg (Västra Götaland).