Need help I have a 70s twin hustle but it has no stand-by switch however the internals are exactly the same as the schematic the other oddity are the knobs can somebody help. My friend believes it could be a proto type I say may

Here is a picture

Hey I have a n old orange amp here and have a problem with the vibrato the bulb doesn't flash ? But as I look at the circuit I think there should be a capacitor across the 3rd resistor in the picture could anybody help please