Mike,
I haven’t seen anything like that, but I’d sure think about making them from styrene.
First, they’re going to be behind “glass”, so you won’t need a lot of detail.
Thus, you can take some short-cuts. For instance, you could get some Plastruct I-beam for the lower part of the lever and just glue some styrene rod pieces on top. Then, another piece of styrene glued at an angle and, voila, you have the levers built.
For the base, you could just bend some .020 styrene sheet over a slight curve. While you could cut slots, you could just use a “Sharpie” to draw some dark lines on the painted plastic.