Some Shop-Vacs missing screws

This isn't a question, but rather a PSA regarding some Shop-Vac models. I have two Shop-Vacs, a 5 gallon and a 6 gallon model. They are essentially the same motor, the only difference that I can see is the collection bucket size and the colour - one has a red bucket with black top and vice-versa on the other one.

I disassembled one of them because I had an issue with smoking and a burning smell. It turned out it needed to be cleaned and a bit of oil needed to be applied to the top bearing. The first unit that I disassembled was missing a screw on the motor housing - but did not know at the time. When I started assembling the unit, I thought was going crazy because I was one screw short. I ended up using another similar size screw I found in my workshop.

It wasn't until today when I though I would do some preventative maintenance on the second Shop-Vac that I noticed that this one was also missing a screw - in the same place! Someone not doing their job properly? Very strange indeed.