That looks like a copy to me. The writing doesn't look right and never buy a Leica if it shows no picture front on with the lens off, so you can see the cam.
The top plate is the right size and shape for a Leica III (or II, for that matter) - which would mean the rangefinder would have to match it - which would mean the focus mechanism would have to be exactly where and what it's supposed to be in a Leica II or III - which suggests this is a Leica. The lens I have greater doubt about, because of the stylized f -- none of my Elmars have that. But it's not a Fed lens (the most Elmar-like Russian copy) - the aperture selector is the right width for an Elmar.
There is the slight possibility the top plate is from an old Nicca, which seems to be the closest Leica III clone -- but I don't know if they made any Leica II copies.
It does indeed looks like the rangefinder housing for a III, the II didn't have the magnification-adjustment.
That shutter button collar in this style is not something I've seen before.
The whole thing looks fishy to me to be honest. Might be a Leica II body built from different parts, but it's definitely not what it's dressed up to be.
The surrounds of the rangefinder windows are wrong, the Elmar f18 engraving appears to differ from mine the line to it is an inverted L, also the lens is marked 5cm f3,5 (in that order),
The Elmar looks the same as my 1936 with serial number 332613. Mine is a little more beat up and not the fancy gold color but the lettering including the different style f look the same.