Are you running the zones at least at green con to you? The shards drop in small chests. Try the zones in Fens, the sunken one and lab is where I used to go. Granted I wasn't hunting specifically for the shards, was more doing zones, but I'd finish with a few in my bags. Good luck!
and i believe they drop mostly off trash mobs. so don't bypass the small chests thinking there's another carpenter recipe book in there lol
And they seem to come in streaks. You can run that zone three times in a row and never see one. The next time you run it, almost every small chest will have one.
I got one in seb last night but I was there an hour mentored on a 110, so not so good drop rate there, also they r running 23k on Skyfire, 43k on majdul, 28k on HoF on the broker. So not so affordable to buy a few either.
If all you're after is the trophy stands, you can buy them from Shazra in Sapswill's Rest (Tranquil Sea) for 20x Far Seas Trading Company Tokens. Of course, you have to do a few tradeskill quests to earn those, but it's less troublesome than trying to find the shards.