The cut of the beads in your second and third pictures is a dead giveaway that they're likely phenolic resin. I don't quite know how to describe it, I just think of it as the "zig-zag" or "reverse triangle" cut - an attempt to make the beads look more nugget-like rather than like sliced cylinders. The 4th bead from the bottom right in your second picture displays very clearly the wavy edge resulting from this cut - and, once recognized, you can see it in most of the other beads as well.

The red appearance seems to be due to dye, either applied during the casting or in a bath afterward, I don't know.

The beads having this zig-zag cut generally seem to be in better condition than such examples as in Carl's photo, so I wonder if they're a few decades newer.