[Mondial]

The wire wrapped around the capacitor (inductance) and the capacitor itself form a series resonant circuit, broadly tuned to the IF frequency. Because circuit ground is isolated from chassis ground, it is important that the impedance between them is kept to a minimum. Otherwise IF oscillations may occur. At the series resonant frequency of the wire coil and capacitor, the AC impedance effectively approaches zero, thereby efficiently bypassing circuit ground to chassis.

This technique was more important with the old type paper-foil capacitors which had a lot of parasitic inductance, making an effective bypass difficult. With modern film capacitors, series inductance much less of a problem.

I would guess the designers of the radio had a problem with IF stage oscillation, and went to the wire coil-capacitor as a solution. Can't see them doing this otherwise, as added production time and cost.