ckdamascus, you've guessed correctly again - After discovering the 'final' item in the closest tree cache, my quest log now shows 5/5, and the next step actually tells me to bring the goods to Ratmir, but, again, there is no conversation option to finish the quest. *Arrrrghh*!
Even trying the 'item cloth_pack' again, in hope of retriggering the quest has no effect. I guess the only other option now would be to delete and re-add the cloth packs, but no one seems to know the syntax of the required delete command.