Possibilities
Hooky,
Lots of code lines and titles need to match up for a ship to appear. I hope this is the problem as it is the easiest to fix.
I'm not sure if HMAS_Melbourne is the ship's exact name, but it will suffice as an example
1. Folder Name: HMAS_Melbourne
Model folder > model.cfg
[models]
normal=HMAS_Melbourne
3. DP file (or sim name): HMAS_Melbourne
4. Ship.cfg file:
[fltsim.0]
title=Your choice. This title shows up in the drop down menu in the MB
sim=HMAS_Melbourne
model=
panel=
sound=
texture=
The red lines must all match up or be the same. If not, the ship won't show.
I hope that the problem lies there.
If not, check your texture folder name within the HMAS_Melbourne folder. Make sure that it is just the default "texture"
If it has a specific name, such as "texture.cammo" then that specific name must be listed as such in the "ship.cfg" file.
E.G.:
[fltsim.0]
title=HMAS_Melbourne
sim=HMAS_Melbourne
model=
panel=
sound=
texture=Cammo