Hmmm... went by Allakhazam's and they have no info on the quest... how odd.

First thing's first, you must get a Star of Odus (buy it) from the jewelry
shop in Erudin. Turn it in to the *MALE* banker in FV. He will then give
you a 6-slot container with a combine button for the coins.
Since you already have the ones from Dalnir's and Kaesora, we'll skip those.
City of Mist- One drops from the Captian of the Watch (or something like
that, I lost my detailed list :o/ )
Emerald Jungle- Must be Foraged for. Grab a nearby druid and exchange a lil
mana for the foraging ;o)
Lake of Ill Omen- The Bloodgill gobbies in the lake (look at the base of the
pillars around the center of the lake) carry these, and are probably the
toughest creatures you'll have to fight in this quest.
The Overthere- Check out the big pit in the center of the zone and kill a
scorpoid (can't remember the exact name, but it's the rarer of the two kinds
of scorpions in the pit).
-all of these coins are fairly common drops-
Put them in the box the banker gave you, hit combine (now it looks like a
treasure chest), give it to him, and Voila! you have a Nostrolo's Tamborine
(and you will notice the difference IMMEDIATELY).

NOTE: Make *SURE* you have an empty spot in you general inventory for when
he gives you the box for the gem (not sure about the tamborine, but always a
good idea). If your inventory slots are full, you will get the "dropped to
the ground message" but the box will be gone (ie: time to head back to
Erudin again).

Enjoy!

-=B=-
The Rathe
On Strike
(Remember, the Bard strike hits Bertoxxulous server *THIS* weekend in
Kelethin (at PoD), at 9PM CST)