Just wanted to add my two pennies in here too: I own the double mini heart tag with enamel blue heart as well and in addition to the scratches, there's a small bit of clouding on the RTT mini tags on its front top right hand side and back top area.
I've tried polishing it to no avail, and I haven't worn this piece as often as some of my other RTT tag pieces. I'd try a dip except I don't want to damage the pretty blue enamel.
Also, back on topic to DBTY - it seems diamond specs are not included for the collection on the UK website. I click on a carat size to add and it goes straight into my basket. For the much more expensive pieces (eg. platinum), I'm told to call customer services. Perhaps it's something I need query about in person? If so, I'd better wait for all this Xmas and Valentines day hoo-ha to die down (plus it gives me time to save more funds... three bangles are not cheap, but I am not allowed to wear them yet!).