Most of us have at least an electronics trade school certificate, some are working the field, some are repair vending machines, and others have at least a bachelor degree or more. I am unable to identify the circuit. It has one vacuum tube, which makes it a 1950s to 1960s vintage. It has a lot of knobs and switches mounted on a chassis. To identify this circuit, you will need to find a schematic diagram, that might be sticker on the chassis or find someone near by who is an older person from that era who likes electronics, maybe an amateur radio club? You could study the circuit by drawing a diagram yourself, because most vacuum tube circuits were point to point wiring, not impossible to draw like printed circuit boards. Try drawing a schematic diagram of an Asus motherboard in your desk top computer. That would be an impossible tasks, unless you worked in designing Asus boards for Asus. Vacuum tubes are used for amplification or rectification. This is your project. It can be an instrument, or an audio amplifier, too. We do not know.
Lawsen