EDIT 3:
After a bit of testing and a harsh beating from my coworkers that had no mercy while using those I have decided to create new one. It should be more sturdy, I have replaced slide in cap with threaded one so it will not be so prone to breaking. (that was the most common issue with this model). It has other shape so it is also printable without supports.

You can find new model there:

https://www.printables.com/model/1307534-milwaukee-rivet-container-revised

EDIT 2:
New cap is pretty tight but it fits and locks on place. For locking it i just slide it in with a bit of force and if i want to get it off Im lifting the back with the locking notch a bit with my thumb. 

EDIT:
I have noticed that the cap after a bit of use slides to easily so I have added a v2 of the cap with a notch at the end to block it on position. I have not tested it yet tho as I have a week off so I will update after testing.

The rivet containers at my job were getting damaged pretty fast (from around 5/6 tools only one new have a container and cap is fixed with tape as it is not holding) and the caps were get lost all the time because they simply does not hold I have created a replacement model. It is just a bit bigger, thicker and a cap is a slide in from the top so it should hold better than the original one. I have printed it myself in petg without problems (set like on the picture from silcer). 

Leave a like if you liked the model ;)