That looks like a whole bonnet respray job.
Chipsaway etc could do it, they use airbrush for small marks and bigger sprayguns for panels. If you have a Chipsaway unit nearby then easier for them than the mobile vans as the workshop would be better for bigger jobs. Van based have portable awnings but a bonnet is a big area to dry even with their infra red heaters!
I would definitely treat for rust ASAP and give the bonnet a waxing to help repel water until bonnet is resprayed.
