There is a bank in Keldagrim, so you don't have to carry everything there. Once you're there, take the items out for use in the quest.
Enemies to defeat
Enter the tunnel to the north-east of Rellekka, close to fairy ring DKS. As soon as you enter, walk east and enter the cave entrance shaped like a crack in the wall in between the two statues to go to Keldagrim.
Talk to the Dwarven Boatman inside the cave. (1)…
Yes, I'm ready and don't mind it taking a few minutes.
After the cutscene, cross over the bridge to the west side, go to the Black Guard H.Q. and there, continue the dialogue with Commander Veldaban. (2•✓)…
In the event you do not possess the ore or bars the secretary or director assigns as your task, you do not have to accept it, simply cancel the dialogue and request another task. This may make you have to do more than 4 tasks though as you may lose favour declining too many tasks.
Run west to the marketplace building and up the stairs.
Talk to any secretary - your character's gender may disqualify your eligibility to work for that colour of company, consequently try another colour. (3•~)…
Is there anything I can help you with?
Fetch them the required ore. (Repeat for a total of 4 tasks)
Talk to the director. (3•~)…
Do you have any more tasks for me?
Fetch them the required bars. (Repeat for a total of 2 tasks)
Talk to the director. (2•3•1•1)…
I'd like to officially join your company.
Blasidar the sculptor has sent me.
I would support you.
Yes! Long live the [company]!
West of the bank, return to Commander Veldaban. (1•2•2)…
I do NOT want to attend, I don't have time to waste.
I just have a lot of smithing to do today, I can't attend.