Thanks fellows for the nice comments on the the radio!
The tuning knobs have a numbered scale, 0-100. The reason that the dials don't read in frequency is because this radio pre-dated the structured 530 to 1710khz am frequency allocation for the BCB. It's that old.
Since this radio is a "TRF" (tuned radio frequency) set, and not a superhet, it is tuned differently than what you are used to. Each dial tunes a separate RF stage. The signal passes through each stage and increases in strength until it is rectified and "detected'... turned into audio.
Once you hear a station, you very carefully "rock" each knob back and forth to find the peak in that stations signal. As you keep doing this from the first knob to the third knob, the signal keeps getting stronger in the 'phones. Soon, the tuning gets very sharp as all the tuned circuits reach resonance. It is at this point that the desired station is the loudest and the tuning is the sharpest for maximum selectivity.
The small knob to the right controls the filament voltage to the three tubes, and acts as the volume control. Strong signals need less filament voltage, and weaker signals need more. The small knobs underneath the large knobs act as "fine tuning". If you press them in ( they are spring loaded), and turn them left or right, that will cause the main knob to move slowly for a "vernier" effect. This makes it easier to tune the circuit when the tuning has become very sharp.
Yes, so far I've seen some pretty cool gear on the pages of this thread!