Well, first it should read "Inhomogenieties at the interface". The interface is supposed to be smooth except where distorted by the microtoming process.

I think you have misunderstood the Kahn photomicrograph. This is a 10 layer structure. What you interpret as silver being unevenly distributed is two layers as follows /overcoat/fast yellow/slow yellow/CLS layer/fast magenta/slow magenta/interlayer/fast cyan/slow cyan/AH/support.

The fast layers are coarse grained and the slow layers are finer grained. That is what you see as inhomogeneity and that is what can be seen by the light as changing the nature of the layers.