[tab10672]

As you said, the radio would have had large black knobs 2 or 3. Cabinets were made to hold the old regens and trf's. Rather than a speaker it should have been some type of horn reproducer. I have a couple cabinets like this (not near as fancy as yours) and rather than hold a chassis and have a panel for the knob shafts to stick through you would set the entire Radio/box on the top and the horn on bottom there was usually also a shelf to hold the batteries.

So to answer your question... An old 3knob trf would look correct and although they were popular in the 20's rather than the teens a trf would be much easier and cheaper to find than something made in 1918