Note that there are still one or two claws and other items that have not converted, though it's a very small number for only a couple specific things.
Those that don't convert are 'required' mats (for things like the champ stun horn) and not crit items.
There are barter vendors in a couple places, Est and MD. I think there is another but I can't remember right now.
also:
NOTE! many of the old items convert into a more than one type of new item... and more than one old item may convert into the same new item... so don't just blindly convert the old to new.for example: great claws convert into 6 different items, 4 of which only come from great claws but 2 can be converted from other items (deadly claw and dusty tail)