I don't think those are beveled or DeArmonds.....but they look proportionally similar.
Page 32 in Hans' Book shows this pickup next to the "Mickey Mouse" type.
Its unclear who the maker was.
Its interesting to see that X-175 with those.....can't remember seeing one like that before!
Beveled DeArmonds (like a model 210 with a bezel for top mounting) show up the most on circa 1960 Starfires and very occasionally thereafter on on a few other models.
I'ce never heard the "plastic" top early Polara type pickups but if they are similar to the brass chrome plated Polara type they added some grit to the sound of that X175!
I've always thought that a combination of Mickey Mouse and the chrome Polara single coil pickups would be a great combination but never made such a modification.
M