Dune Cosplay Help

Hello!

I'm looking to get some help in making a fremkit backpack from Dune Part 1 and 2. I'm going to be doing a cosplay come August for Dragoncon and would love to include a usable fremkit backpack.

I remember seeing someone on etsy had made a backpack but cant seem to find it anymore, so any help in tracking one down or DIYing one is appreciated!