Ever tried this? It lets you search Google's archive of scanned vintage newspapers. It will turn up a lot of results that you have to pay for unless you go into "Advanced archive search" and select "no price". Here's sample searches with that option selected: "stereo radio cassette"
"boom box"

It's worth it just for this alone: Homemade boom box model

That's very interesting, thanks. How and where do you select 'no price'? I just got the screen asking for payment.

thanks......thats realy interesting

really cool...thank you

Sorry I thought it saved the "no price" selection in the links but it does not...
On the news archive main page, click "Advanced archive search" which is next to the Search Archives button at the center top. On the Price drop-down, select "no price" and click Search Archives. Now only free results will come up. Have fun!