The part of the scrying Description of the fate on targeting a place says:
Instead of targeting a creature, you can choose a place you have already seen as a target of this spell. When you do, the sensor appears here and does not move.
This does not specify that you must have seen the location physically; any form of "sight" is enough. It's a concentration spell, so you can not have multiple castings of scrying active at the same time, but you do not need to – you just have to see it earlier. And according to the first part of the description of the spell:
You can see and hear through the sensor as if you were there. […] A creature that can see invisible objects sees the sensor as a luminous globe the size of your fist.
As such, from a simple reading of the spell, you can indeed choose a location that you have previously seen through the reading sensor as the target of a new scrying to spell.
The description of the spell does not specify how much you must have seen the location, nor how much the location you choose should be specific. As such, it is up to the deputy minister to decide.