Well, most of the arch has been cut away and i open up the seam a little to aid removing a small amount

this is then cut of just shy of the inner face of the new arch

spots located prior to drilling out

removed

if you wanted to be slack

you could just grind this a bit flat and tack the new arch to the remnant of the old one an d live with a big seam or use the gap to weld it up as often seen, but honest this way is neater and nicer
arch now resting between the remainder of the old inner and the wing itself

a few issues at the rear

so out with the blaster

i have done the whole area whilst at it but the rotten bit will be cut out

here

treated

so thats stabilized for now.
this will need whipping off

here item 'A' is the inside view of the rear jp/arm reinforcing plate and 'B' is the inner wing skin that mount to it and is spotted,

there is a small area of rot in the corner to cut out and a little in the rear bulkhead which will show when i have removed the sound deadening, here's a pick of the other side to put it in context

not much writing as the picks are a self explanatory i think
mm