I have seen that same radio on mid to late 30's Oldsmobiles. Always thought it was a factory accessory.
looks like they had a few different mount designs. And it's missing the big box that contains the radio...this is just the control. https://www.radiomuseum.org/r/united_1_delco_r705.html
Delco R705 Generic to fit any steering column that size. Sold a few of these. One restored and one converted to am fm