Found this note last weekend in the desk of my childhood when I was looking for a small screw to get my mums sewing machine working again. I was always harvesting screws and stuff ... Besides the screw I found those mics and speakers of old telephones which I have used to built a communication device in the late 80s.
Back then you were able to repair a telephone. Microphone and speaker could be easily replaced.., no soldering required.