Heat deterioration which is a cause of metal fatigue (loosing tension) at fuse clips, which causes further heat related deterioration has been a reason for replacement of this type distribution panel.
Look at the photo, 3rd & 4th fuses have 'tensioners' on the fuseholders.
As to the 'open' bare buss and terminations..
I would say...."close the door". However...is this panel only accessable to qualified personel??
John
