[2ndgeer]

Ersatz..
The pictured radios are not mine. However, over the years I've have installed Sony, Clarion, and Kenwood cassette stereo radios in my 1934 pickup (overhead panel). They are all the same size like those in the photos I attached. I bought them locally or from Crutchfield by mail. The simple ones may no longer be carried because the current market sells those jazzy panels that announce the song in letters.
If you want to see a neat option (but VERY PRICEY!) check out this current post on eBay...only $562 but it is 12 volts!!
Here's the item number:
300658619159

Maybe your friend should check out auto parts stores that sell radios (like Pep Boys, etc.) There may still be available economic choices that are no longer popular with the "up to date" crowd.

I bought this restored original F1 radio for $419. I think nothing looks better in the pickup dash of my 1950 F1...and the brackets on the side simply bolt to the steel framework Ford installed behind the dash. Maybe it's too expensive but it sure "fits the bill."