Flakey Bay with weird sills

[rideforever]

Hey, perhpas someone can tell me what I should do with this bay.
The post on the rhs of the center window, I have sanded/ repaired it 3 times still peeling off.
I guess it needs wood replacing.
And then the sills are lead !!! Don't ask me why.
Underneath looks like plywood.
Maybe someone thought they were so narrow you couldn't get a proper sill there.
Or there was a problem getting it watertight so they changed to lead at somepoint.
What's the most cost effective way do get this repaired in sussex ?
General carpenter ? Lead worker ?
Thanks for any recommendations?
How much am I looking at ?
Cheers

(the blue bits are the damaged areas)

 

[Wayners]

Strip paint off.
Clean lead and treat.
Painting lead is never a good idea as it peels.
Or
General builder as they will advise and project manage other trades if required.