Imas,
Nice little collection.
I would clean them and wax the blades.
If you have the space it is better to store or display them out of their scabbards - They look better and there is less chance of rusting due to moisture in the scabbards.
If in drawers or cupboards then using the silica gel may help especially if you live in a damp or humid climate.
The mandaus should really be displayed in my house
regards
Roy