I've got a single-handle shower (the type where you turn it both to turn it on and adjust the temperature) that's leaking. I'm pretty sure I need to replace the cartridge, but I can't find any marking of who makes it. The cartridge looks like a metal square stem coming through some plastic gears, and the trim is remeniscent of Kohler's Finial line, but different. I'm attaching pictures of the trim and the installed cartridge. Anyone have any idea what this might be?