https://www.photocornucopia.com/1061.html only lists the EL which are 6 elements in 4 groups. I had a 3 element 50mm that came with Durst I bought like 20 years ago, very poor lens, even for a 3 element.
Omicron EL 50, 2.8/50 6-4 2-20[52] N 8[52] 39x1/26 40.5x0.5[52] 1975 [49][52]
Omega Omicron EL 75, 4.5/75 6-4 2-10[52] N 8[52] 39x1/26 40.5x0.5[52] 1975 [49][52]
Omega Omicron EL 90, 5.6/90 6-4 2-10[52] N 8[52] 39x1/26 40.5x0.5[52] 1975 [49][52]
Omega Omicron EL 105, 5.6/105 5.6-45[52] 6-4 2-10[52] N 8[52] 39x1/26 40.5x0.5[52] 1975 [49][52]
Omega Omicron EL 135, 5.6/135 5.6-45[52] 6-4 2-10[52] N 8[52] 39x1/26 40.5x0.5[52] 1975 [49][52]