It was a state institution dealing with the taxes paid in corn. There were store houses all over the country for that purpose.
'Vaktmästare' means guard, caretaker, porter, attendant. I would guess 'porter' or some kind of lower clerk at the direction in Stockholm.
The bottom signatures are those of the two who guaranteed that the spouses weren't already engaged with someone else, not in too close kinship, did willingly marry, of legal age etc. Note that this document was written some time before and not at the marriage.
(Meddelandet ändrat av christerkalin den 26 april, 2009)