I don't think Fett has greeblies on his bottom. (Sorry, had to).
Honestly, I don't believe there are greeblies added to the underside/bottom of the jet pack. There are decals/symbols toward the bottom on the back of the pack though.
I would love to see a pic if someone has one of the very underside/bottom of the ESB jet pack though.
I don't know if we will ever know this answer. I would have to imagine yes, if Pre-Pro and ROTJ did. We just never got any visual reference of the ESB pack from the under view.
Well, actually I am doing a complete pack repaint for another member, but since you asked, here is my prototype in the works...........
I have not decided if I plan on making and selling these yet, but time will tell.I am trying to modify everthing so it is less time consuming.
I would have started a seperate thread, but it would be quite a bit of time between updates, so I decided to save forum space.