Aridus Industries is working to bring the CROM (Co-Witness Ready Optics Mount) to a levergun near you. They recently shared images of the prototype mounts for Marlin 336/1894 rifles.
The CROM features an integral ghost ring rear sight and an optic specific mounting point (Aimpoint Micro and Trijicon RMR models shown). The design allows the optic to co-witness with the iron sights.
Stay tuned for information on pricing and availability.