It's a Mr. Freeze body, which shared the arms and legs from the Lex Luthor that came out after Mr. Freeze did. So yeah, you could say they are Luthor boots.
The figures contained in the Custom Showcase are not for sale by Figure Realm, and the creators of the customs are no way affiliated with Figure Realm. The Custom Showcase is purely for entertainment purposes and only provides a means for the creators to show off their work. Figure Realm does not make or sell customs.
