Thanks everyone for the interesting and encouraging comments.
Now we turn our attention to the bow door. It comes in two parts, which is going to make it easier to make the damaged bulge thing.

The PE set comes with replacements for the draw bolts in the form of sliding thingies. I was originally not going to bother because I thought they looked ok, but then I thought ’If I don’t use these bits now I never will,’ so I went for it and dutifully removed the plastic bolt detail and assembled the sliders.

There was some ambiguity in the destructions about where they should sit so I went through my references and all but two pics , one of which is a restored example, showed the bolts as per the original..... But all the contemporary pics show the bolts. DAMN!
I can only take artistic licence so far, so now I have to remake the bolts grrr.
So while I think about how annoying that will be I will get on with the bulgy thing.
So the first thing I did was cut off the steel beams , as I am going to replace the bulge with one made from copper foil. I don’t remember why I have copper foil- maybe one of the kids used it for an art project...but it’s ideal for what I want.
Looking at the refence pic there is a clear horizontal seam which will make life simpler than trying to mould a flat sheet into 3dimensions. I cut two pieces using the original as a template.

Then I traced around the original on a piece of 10mm foamboard, from which I stripped one layer of cardboard and shaped it to match the original

I pre-crinkled the copper and glued it over the foam using foam-safe UHU, which will take ages to dry so I've masking taped it to death.
When it’s dry I will remove the card from the back and stick it in place on the bow door. The foam will (in theory) support the foil and allow me to further distort it if necessary.
See you next time
Neil