[Miken]

There is a cone mounted to the grill cloth board that  fits inside the speaker on the radio. What is that for. Thanks

[rfeenstra]

High frequency dispersion.

[morzh]

Make sure it holds well.
Those are known to fall off and damage cones.
Also when removing-replacing speaker, make sure you are being mindful of it being there lest it damages your cone.

[Miken]

Thanks I’ll watch it, did not know it was there when I took it off.

[morzh]

This is exactly when most damages occur.

[rfeenstra]

Morzh is right. Don't ask me how I know.