Fm Radio Mounting Bracket

[Rakort]

I installed my newly acquired FM radio today in my 68. I was fully expecting to be able to reuse my existing AM radio bracket that drops down from the speaker bracket and hooks on to the back of the radio. Basically to keep the radio stable.

To my surprise there was no means on the back of the FM radio to attach said bracket. I ended up installing the radio without the rear bracket.

So how were the original FM radios mounted? Just with the nuts and cups around the knobs with nothing underneath? Or was there some other type of special bracket for the back or underside of the FM radio that I don't have?

Thanks
Rakort