Sorry about not posting the photos when I indicated I would. I've had an issue arise, that took priority.
The canvas lid cover did indeed get cut, and it's now been finished. The leather strap also in the photo, will go around the edge of the lid to secure the canvas. The manufacture of this box is quite different to the tool box I worked on some months ago. There is about a 1/2" gap between lid and box. This is because the thicker part of the hinges sit between the box & lid, instead of outside rear, as was the case with tool box. Therefore, 1/2" gap! Which I don't like, personally. Too bad, that's how it is, so I've gotta deal with it. Secondly, securing strap isn't recessed into the lid as far as tool box, making it tricky to make a satisfactory canvas cover. You will notice a rectangular hole in my canvas. That's to slip over the securing strap. The original wasn't like that, but if I copied that way 100% there would be an ugly gap in the lower 'skirt' of the canvas. Having already said there is the 1/2" gap, I didn't want to have any break in canvas to expose said gap. Hence the strap poking through my canvas. I think it looks OK.
The box took an awful lot of filling, to get rid of the cracks and surface blemishes. The large crack I had previously filled with wood glue, and had to remove a few millimetres depth of that to have sufficient purch for the filler.
It took several, increasingly shallower, applications of wood filler, before I was happy to proceed to the next step.
While waiting for the various layers of filler to harden, I straightened and blasted the brackets and locking latch. I found my bottle of gun blue, which I use for etching and darkening the steel parts, was considerably emptier than I had expected. As a result, I could only make a token effort with treating the brackets. I'll get more tomorrow, on my way to Nambour.
To be continued....