Sagging cast iron gutter under slate roof

[droglite]

The fascia board is not vertical causing overflow. I think The angle is too great around to pack the brackets .
Does this mean a complete removal of the sagging section, fixing leveling attachments to the rafters and then refit a new fascia board?
The slates are very heavy swithland slate whick is an added hindrance.
Any suggestions..

 

[foxhole]

The facia would have been level , try just extra fixing thru to timber .

 

[droglite]

Thx yr response. The facing would have been level when first fixed. It now leans outward considerably. Don’t understand the suggestion you make.