If you have the burlap sleeves on your toon still ( like my toon that had been in stasis for years), you can destroy the burlap and re-hail. She will give you the new improved arms.
Vahlara hands you this (or the equivalent for the other class archetypes) when you first meet her.
You say, 'Hail, Vahlara' Vahlara says 'I'm glad you managed to escape the slave warrens in one piece. There are many [others] who were not as lucky. Here, take this armor we found on a kobold. It's not much but it should keep you safe.'
(Previously, she had handed out Stitched Burlap Sleeves.)