@Simon, I did some playing around with the sizing and layout and your suggestion of the bare logo on front and details on rear works really well in my mock up. Once you drop it down to a suitable size for the headstock, you tend to lose the text, and the white border becomes indistinct enough to be redundant.
So for these smaller applications it will be limited to:
Attachment 15508
Given that the headstock is slightly lighter than the rest of the body, it should give enough contrast to be visible but not prominent.
I'm going to have a bash at printing a few off and see how they work.