it's really well modeled up mate, and the shadow, light and gi give it a great effect, the only problme are the materials, the metal one looks real, but the black paint just doesn't heres a small recomendation on it, on the reflection add the dispersion to 15 to about 25 and try it, also add a small bump map with the noise or turbulence, nothing to big just 5 or 10%
do a set selection on the handle and reduce the reflection, then use the specular on a low level
add a sky and make a new material, use the color or luminance mode turning all ellse off, and add an image like a photo of the sky or a room, AKA hdri and set mix mode to multiply, play with the setting to 100% to 250% that'l make it look more real

hope its usefull mate