Hi Andrew Cute beyond words !!! Any time you go after a pair do try to stop down as much as possible, dof is critical and will make a difference !!! How much of a crop? btw when increasing the dof do get your ISO up for enough shutter speed, your MK3 performs well and any noise will be easy to deal with .. just don't underexpose at all !!!
In Ps you can lighten the area around the eyes a bit, did well with the exposure and minimal PS is the key !! btw when sharpening do try to sharpen only the animals !!