I'm not sure if this is as far as you wanted to tone it but I converted it to duotone mode and used one of the Tritone presets... BL 404warm gray 401 warm gray ,converted back to RGB, brought back some contrast and saved as a JPEG
There are loads of presets in the adjustment panel (Duotone) located in the top pull down menu bar in Photoshop, and they can be further modified with the individual curves adjustments in each tone.