Having worked on my model for a few weeks, it has started to take form to look like an instrument.
Using the curve tool to make the edge of the body, I extruded from there in order to make the base shape. Then extruded the neck and made the fret board and other components separately.
Here are some screenshots from various stages in the last few weeks:
I believe my model is coming along well, although i realise that my topology is a leaves a lot to be desired in some places (Especially at the arch connecting the neck and the body) – but this being a high resolution model means that this will not be the final game asset, so there is some leeway when it comes to things like that.