If you'd like to keep your build studs up and avoid dealing with the 6:5 ratio, you could try to use Plate, Modified 1 x 2 with Arm Up with the already mentioned Brick, Modified 1 x 2 x 5 with Groove, as the 3.18 mm bar will slide in the groove just fine.
Another option would be to keep the rest of the elevator car studs up, and only turn sideways for a few ...
Lego bricks are not sized similarly in each dimension. The height to width ratio of a brick is 6:5, which means that 2 bricks stacked on top of each other with their studs up are 6 plates high, but the same 2 bricks stacked on top of each other on their sides (studs facing sideways) are only 5 plates high. Said differently, bricks placed sideways (studs to ...
Perhaps something like this using 1x4 arches could work?
This does work out to being 2 modules too wide for 1:1 scale with a GameCube, but the trade-off in accuracy may be worth it to you to get the round ports. It appears to be only 1 module wider than your current design.
Here's more detail of the build steps: