It is possible that the Swedish transcribers for Emibas sometimes mixed up how the dates were written in their hurry to finish. The original parish records need to be consulted. They are online, by the way, if you subscribe to the fee-based Genline site, and they will include much more information than the cd, of course.
Usually the word 'bruk' is used for factory but I suppose that there are many words for the same thing. I thought factory was the meaning when I first looked at this word, but the definition I used came from "Swedish Genealogical Dictionary". Double-check what that occupation means on the Sweden forum where there are some Swedes. (Type Sweden in the "Jump to Forum" space at the top right of this page.)