RB Concepts Boxes
 

I have an RB Concepts hauler bag, and the boxes within have seen better days...

So, i want to replace the boxes instead of the whole caboodle, but I can't find the boxes anywhere, and the ones I have found from rb concepts are either too small or not listed with measurements.

Does anybody know where I can get boxes that are (l) 500mm x (w) 280mm x (h) 140mm?