This is an easy one. I have not heard of anyone finding the trivial lvl to any of the new armor yet. And I have heard non-triv for sure at skill 235. Some ppl are saying not triv at 250 (the cap)
Actually there is no simple answer to the "level to make?" question here. It depends what your goal is...
From reports I've read from more skilled tailors, my impression is: If you want a 50-75% success rate, your skill will have to approach 250. If 25% is good enough, then getting your skill to 200 should do. 5%? Anytime from 131 on would be appropriate. (Don't want to waste a potential skill increase while you still have much easier ways to skill up...)
Cobalt drake appears to be more difficult than the rest of the velious leathers, so I would expect the minimum 5% success rate for a while, probably not starting to increase until somewhere in the 150-180 range.
For certain items even the 5% success rate may be acceptable. Once I get some of those darn drake eggs I'll certainly be attempting the belt, which would be far more useful to me than this bracer.
NONE of the Velious Leathers and Furs are trivial at skill 250, which is as high as you can get, as per Niami Denmother of EQ Traders Corner. And the success rate without high skill is only about 3% not 5%. I do agree with Palarran in that attempting to make a Bracer with these stats is a waste of a potential 8 Wis Belt :-)
druids and necromancers seem to be best able to kill them alone, but other classes can harvest their hides with some work and special items or a group of friends.
If my information is correct, these look all black on a human paladin. Not a bad look to strike terror in the hearts of your enemies! Too bad I'll probably never see them as the ingredients are a ***** to find and no trivial value has been found yet. Oh well :)