Hi @Tommyshandyman,
Welcome to the Bunnings Workshop community, it is fantastic to have you with us.
Yes, you could use the Dulux Metalshield Multi Purpose for some touch-ups, but there may be some slight differences in the colour due to the different formulas being used.
If you are fine with this, just make sure the surface is clean before applying the touch-up paint. Use some sugar soap wipes to remove any dirt or dust that could affect adhesion.
Let me know if you have any further questions.
Jacob
