I'm quite taken by the idea of IA recognition (if not re-use) of carvings. Ask anyone who's had to put up with me waffling on at them. Chatton 4 is smack bang in the middle of a earthwork that's listed as a settlement, and it looks more, well, sort of more 'used' than the other carvings nearby. However, if IA folk were re-using the carvings, it's got to be a pretty slim chance that it was for the original purpose, but then the meanings probably mutated over the centuries anyway.

I've never seen pics, but I recall reading that the complex bits of Traprain's carvings are more incised than pecked, whilst the cups are pecked. Which makes it all even more confusing.