Repairing an early 19thC pistol case

[Flintlock&Steel]

Traditional techniques request.
This case is from about 1840 and it's suffered a bit.
The handle and brass corners are of the "Campaign" type as used by the military as they stack flat and are thus more protected.

The previous owner did some unnecessary work as in stripping the top of the lid of it's old finish in order to polish the brass handle.

The lid has issues.
1) The old glue has degraded and joints separated. How best to remove the residue?
2) Then the ideal way to bring it all together and re-glue? I could use PVA but not sure that's the best approach. It'll need careful alignment then clamping up. Traditional method?
3) The brasswork has a thick layer of oxidisation which can be removed. I've used vinegar in the past but is there a better way. Given the proximity to the timber I don't want to damage the old finish.
4) I'd anticipated brass screws but these are steel. The case having once been damp the screws are part rusted in and awkward to remove. I'll go for brass screws when replacing them but from where?
5) Toning the lid. Again looking for a recommended way of achieving this. I'd prefer not to resort to a modern stain
Any help appreciate

 

[KlumceE]

Try to gently soften or scrape off the old glue without harming the wood, then re-glue using hide glue or good PVA, clamping carefully for proper alignment. Clean the brass with a mild abrasive like jeweler's rouge or a baking soda lemon paste to avoid damaging the wood . Swap the rusted steel screws for brass ones from a specialty hardware store, and for toning the lid, traditional shellac or diluted pigments work nicely without using modern stains. I hope this helps

 

[Flintlock&Steel]

Thank you for the guidance. I'm hoping to have time at the weekend.
With having the brass corners it all has to be glued in 1 go.
The screws that came out were old style parallel sided, tapered point. I can make some in brass on the lathe but making 8 will take some time.
I've had some success cleaning brass with vinegar but might try your suggestion as there is a good layer of something on the surface. Don't want to take it back to being bright, totally wrong.
Actually the handle need to be toned down as it looks a mess as it is.