Looking at that laser engraving I would say that it is not actually burnt into the aluminum so a ghost image is unlikely. Or at-least not something that would be a pain to remove. Now what I have seen with laser engraving is terrible pitting. I have only seen one that didn't pit and it was never actually used for play.
Here is an example of pitting. This marker had full gun laser engraving.
If you plan on getting it re-anodized please do not sand blast it. Not only is it way to aggressive, but being that you used it for steel the sand is most likely contaminated. With anodizing prep everything has to be dedicated to that metal.