Hi Josh,
The inner width of 75mm +/- 0.5mm is a very "precise fit", as the circuit board also measures 75mm.
You have to stretch the housing a little when inserting the circuit board, but of course it holds firmly.
The main problem is part of the positioning on the board, an area is a little under 3mm from the edge of the board - this can lead to collision problems, as the grooves inside the housing protrude approx. 2.5mm.
The component height of the capacitors in the area was also a problem for me, which I could only solve with a lot of "dremeln".
The 27mm depth, on the other hand, is only a problem if, like me, you want to use the larger 4mm safety sockets, otherwise not.
Martin