Okay, I know this looks pretty good, but I *WAY WAY* cheated.

I took the map into Photoshop, desaturated, inverted, then proceeded to paint black around the decorative parts, teaked the darkness and saved as a Displacement Map.

I attached the Image_Map Node to the Bump plug with a  value 3.

Way more trouble than I wanted - but I guess you have to work hard for the good stuff.