I am looking for recommendations how to lower the noise in this preamplifier circuit
I'd rethink the operating point:



I'd be inclined to run at 0.5mA or 1mA, judging from the right hand plot.
The left-hand plot gives us no guidance, because your carrier/info/modulation will be 475KHz. 

Your test circuit (grounded emitter) has no ability to reject power supply noise. Stick 1Kohm in that VDD line, and drop in 1,000uF cap. Your F3dB of 0.16Hz promises 60dB atten at 160Hz, 58dB at 120hz, and 52dB at 60Hz. Now you can trust what you see on the scope as being random noise.

Consider an adaptive-bias, so temperature changes and VDD changes are less of a problem:







simulate this circuit &ndash; Schematic created using CircuitLab