The main issue with the DML etch waders is there are no taps to help join the edges when folded, I looked in my local shop for some "L" shaped white plastic Strip Styrene [ evergreen 292 Angle .080" (2.0mm)]

Starting with the base on the Sherman engine deck.

The 2 waders are just one piece, so just need to bend the top by rolling it over a scalpel handle & then one small piece of "L" plastic.

The deck waders fitted

The rear wader base is made of 4 pieces,this is the front piece with the 'L' pieces add.

The back end of the wader base

Lastly the front & back with the "L" shape strips protruding above the base to help give the top wader part something to hold onto.

also the side strips ready to add (these should have two fold lines but only have the lower one so you have to work out & fold the top part yourelf).