Davide Gironi blogs a vintage guitar amplifier build:

I’ve built this guitar amplifier from a 1950’s turntable with speakers. This turntable was built by LESA (Laboratori Elettrotecnici Società Anonima).  It was left in an house with water leaks, the water was running just over the turntable. Luckily the speakers were intact. Because I liked the turntable front and the speaker cases, I decided to build a small guitar amplifier out of the pieces.

The speakers were obviously old. They both consist of a woofer and a tweeter, joined together using a single capacitor filter. The original speaker impedance was 3.2 ohms. In order to connect the amplifier board to the speaker, Davide connected the two speakers using a single filtering capacitor.

See the blog and the video below for more details.