Are the grooves really that small?
Electron microscopes are certainly the cutting edge, but maybe other more accessible kinds of microscopes or magnification devices could produce similar images for evaluation if one were interested enough to try?
according to wikipedia:
"The (electron) microscope has a greater resolving power (magnification) than a light-powered optical microscope, because it uses electrons that have wavelengths about 100,000 times shorter than visible light (photons), and can achieve magnifications of up to 1,000,000x, whereas light microscopes are limited to 1000x magnification."
I think 1000X magnification would do it well for record groove details.