For the Ik Gran coin, the Captain o the Guard drops the key for the door for the first Black Reaver so if there is a group in CoM you should be able to tag along and get them to help you.
He will drop the key every time, the coin is uncommon.
To find the best place for him, go to the left from the zone in (mobs here are lblue sometimes to a lvl 56 bard so be carefull, an invis versus undead will help a lot because almost all mobs there are undead, you only have 2 or 3 golems but they can be skipped with the server tick trick).
In the stables on the left you will find anywhere from 1 to 4 captain of guard who can all drop the coin and who will drop the key.
Hope it helps for people who want to do the quest for old times sake :).
Edited:
Also added a bit for the coin from the Blood Gills in LOIO, the coin is a rather common drop of mobs who can be kited by a bard with maxed swimming untill you get to the beach near the waterfall.
There you can kite one of them or more without too much trouble, they drop the coin in about 1 out of every four kills.
The Blood Gills themselves are on the bottom of the lake surrounding the entrance to Veksar and don't swim too fast, they hit fairly hard for their level but are not very resistant to dots (magic dot for instance for the lower level bards who want a challenge) and you get them in groups of 2 at each pillar in front, one on either side of the entrance and four groups of two on the building next to the different pillars (one on each corner and two on top if I am not mistaken).
Have fun. (btw, Veksar is a fun zone for mid 40 people if you have a full group and stay at zone-in but keep an eye out for trains, ok xp and some ok drops for entrance mobs, you will need a rooting class for possible goblin adds).