We really can't see much from the tiny photo, other than I can see they are graduated.
There was a thread a few years ago posted by someone with a strand of pearls of this brand. We thought they were cultured akoyas.: Sea Island Pearl Necklace
"Momme" strands ranging from about 3-7mm were commonly sold in WWII/Korean war times, to soldiers and other people working in Asia. The graduated strands cost less than a straight size strand would.