Key buzzer to chime

Did a little bit of research last night but wasn't able to come up with anything very promising.

Couldn't tell you when they started to use a chime. And I wonder if at first it didn't use the radio speakers to do so. I did find a box that at least looked small enough to work, from a Ford Thunderbird and others, but didn't look into how it worked (speculating it used the speakers). Found some info on a Chevy truck site about disabling it, and they talked about it being in the middle of a circuit board. Doesn't sound like that setup used the radio speakers to make the chime sound, but it didn't sound like a good retrofit, either.

Funny thing is, most of what I found were people asking how to disable the chime. And here we are talking about how to retrofit it. :-)