H. C. , Jul 12, 2005; 04:27 a.m.
I'm not sure that lens separation will appear differently on a Leica lens than separation on a large format lens such as a Rodenstock. Perhaps, someone else here will be able to tell you.
On a Rodenstock lens... most of the delaminations I've experienced start from the perimeter and it has the appearance of "oil on water." There's a coloration where the separation is. And, if you look really, really carefully... you'll see a delineation or line of demarcation. If you can imagine putting a bit of glue between two pieces of glass and squishing it together... the demarcation line is where the glue line ends.
Hopefully, I'm explaining it in a way that you can understand what I'm getting at.
As for the cost to get it fixed... someone else is going to have to provide the answer to that question!