The MOW jetpack definitely isn't the cleanest cast jetpack out there, it takes a LOT of work to get it to be smoothed out and flattened, plus filled in. I disagree with the commenter above that the props weren't clean to begin with, if you have ever seen or held originals in your hand like I have, you know that they didn't mess around when it came to making props for the movies as good as they possibly could.
I've put probably 18 hours of work into my MOW jetpack, and I probably require 18 hours more. Thank goodness that my Fettpride jetpack is amazing, the most accurate jetpack out there and it comes primed and ready to paint; no messing around.
I would recommend to you that you make the jetpack as good as you want it to be. I would fill in every pin hole, fill in every one of those pits you find, and make it looking awesome. You will feel better when it's all done, and the jetpack WILL look better.