OK, understood. This is what happened (at least how I have understood it). The father Christopher Fabritius working period as a coin guardein (møntguardein) was 1749-1761 and continues as a town/head guardein (stadsguardein) 1761-1787. His son Fredrik Fabritius' working period was 1787- 1823. But he died and his farther took over to 1823. The control mark on the spoon belongs to Christopher Fabritius not to Fredrik. Fredrik's marks looks a bit different. Please note the year on the spoon 1764
! many sources attribute the control mark on the spoon to Fredrik, which is incorrect. It is Christopher's punch! He used it after his sons death. That causes confusing. This has been discussed earlier in this thread:viewtopic.php?f=24&t=46937&p=139555&hilit=Fredrik+Fabritius#p139555
..it is undoubtedly a bit complicated....and unclear too...