Advanced UV unwrap and bump map / displacement problems First post here! I've been searching and searching and can't find a solution to my problem.

So basically I'm wanting to model myself a ring with the surface of the moon on it.

So the first route I thought of was to try and UV map the top surface of the ring then I could maybe use a bump map to get the geometry I want. But when I tried to unwrap using the follow active quads it didn't unwrap in a uniform way allowing my to get a realistic surface of the moon.



So I then tried separating the surface that will have the moon texture on and tried applying a displacement modifier, but cannot figure out how to get control over how the image is stretched and hence displaced on the surface.



I've watched hours of tutorials to no avail and would really appreciate some help on firstly the best way to achieve my desired results and secondly how to get around my problems!
I think I've done what you appear to be attempting and using of all things a moon map texture designed to be unwrapped on a sphere, certain I'd have the same problem.

I UV unwrapped it using 'Smart Unwrap' and got good results albeit with one section showing an annoying area at repeated intervals.  

Because this was aligned along the ring's circular surface , I went into the UV editor and rotated the image 90 degrees.  Then rescaled and dragged all the outer surfaces in the editor to eliminate that pattern.

The end result -