The front band is consistent with trends, e-block has a grouping (and Andy is right, dou is Slovakian, and there is a difference) :
1944 dou 1374 / HMFB (serialed-probable e/135), SRB (serialed along bottom)
1944 dou 3184 / FB m/m, SRB (3184 RBSW)
1944 dou 4658 / SFB (4658), SRB (4658 RBSW)...