If you decide to use this pattern remember to double check the dimensions and change them to your needs. Also take into consideration that this pattern (like most of my patterns) is not perfected in any way as I only have made one of these so far.
Thinks to be aware of is the spacing of the holes for the handle in the metal strip. I made them 18 cm apart but it really depends on the width of your handle and the billets.
Regarding the billets I might make them a tad smaller next time. Also if you do not want the extra d-ring for the shoulder strap the strip on the billet should be shorter. This again will change how the holes in the metal strip should be placed.
For the gusset I made the channels for the bends 1,1 cm from the edge. You might want to take this down a bit to maybe 1,0 or 0,9 cm instead. Adjust the pattern accordingly.