I posting these photos for more of a reference thing. Some of the Herters lube sizers didn't use Lyman style dies, some used Saeco, and I believe others used a proprietary die of a different design.
When I got this, the Die retention screw was twisted off, I drilled it out and as you can see in the bottom photo, I drilled through the die and into the center post as well...opps I'm quite sure that die isn't hardened steel ...and check out the size of the lube port holes in that Herters die ...YUGE !
I sold this some time ago, and these are the photo's I posted when I sold it.