Over on the Antique Radio Forum, there’s a gathering of grid-dip oscillators.
One of my contributions was this Heathkit HD-10-A Tunnel Dipper.
It uses a tunnel diode as the active device in the oscillator.
The oscillator level is metered by a circuit composed of a few transistors driving a D’Arsonval meter.
The top originally contained a foam cushion for the coils, but that disintegrated long ago.