Sustain piano pedal and change of key from E minor to B minor

 At your risk.

The Mic(s) and the Piano

 At your risk.

Just a Microphone Cartridge, update

 At your risk.

The microphone cartridge mentioned in the previous before previous post is more probably a Shallin D-26A. A heavy cartridge compared to similar looking ones. It is whitish color with a black plastic protective mesh. Soldering connections are on the underside than at the side.