You engrave lots of images on the inside of the barrel.

Congratulations you are now an Expert Engraver!

A groove in the wood is soft, and tiny slit creates a peek hole.

You peak through your tiny peek hole.

"Vat is in ze barrel?"

Do your best immitation of what you think a barrel full of stumble bumbling fluffy wamblers would sound like.
+1 for stumble bumblings

-1! They will want to investigate them! Who wouldn't want to open a barrel of fluffy wamblers?!

Instead make sounds as though you are filled with water. No dwarf would open that barrel. Use your kobold wiles to sound like water, not alcohol. This is important. Also, everyone knows dwarven barrels can't leak, even if left outside for centuries. We are therefore fine.
Just try to sound like whatever would attract the least attention.
What would attract the least attention is whatever our dwarf/elf are just about to tell the official, right? So maybe we ought to sound like something sitting waiting, still to be described, rather than it risk sounding like the barrel full of flour sacks is infested with vermin...

You cover the peek hole and wait for your cue.

The dwarf with the goggles mumbles "hrmmmf grrmmm Shells hhrmmm"

"Zer are no schells in zis fortress..." replies the dwarf with the clipboard.

Aweme says, "What Bembul meant to say is, 'It's honey!' We are just bringing this fruit and honey to the stills."

You try to sound like honey.

"Ve have no time for zis. Somesing triggered ze fortress defenses and killed a dog. Cog, escort zem to ze burrows."

You are wheeled down the ramp. There is silence other than Bembul's mutterings. You wonder how tall this ramp is.

About half an hour goes by. You occupy your mind coming up with a story about a kitten who goes on cool adventures. You draw the cat on the barrel.

Bembul continues to chant about shells.

The fortress guard finally says, "Will you shut up about the shells mate. We are nearly to the bottom."

The wheelbarrow stops moving.

Wait for him to go Berserk and then tip the barrel over and roll away down a ramp.

"I WILL HAVE SHEEELLS!"

As Bembul goes Berserk you roll right out of the wheelbarrow.

"No, Craig!" Aweme shouts.

OW OW OW OW OW OW OW OW

You are stunned. A siren fills your ears.

Hide behind the barrel on the left!

You hide behind the barrels and assess your surroundings.

Where are all the dwarves?

You start to hear a wooshing sound coming from the ramp.

The ground strikes the Axedwarf and the injured part explodes into gore!

Take Axe, lick the fluid coming out of the barrel, look for who threw the axeman off the staircase, THEN duck behind a barrel. Then proceed to eat one of your snacks, if you have any left.

It tastes like dwarven ale.

You acquire the axe and eat the last of your mantis jerky.

...Go to the door on the left over past the ramp.

You make a mad dash for that particular tunnel.