Retrosound (also Custom Autosound - seem to be the same company) fit nicely with no modification to the dash. At least I didn't need to modify mine. Below is the Custom Autosound 740.

NOTE the first radio I got for this was a Retrosound 230 (I believe) and it had the same fitment as this 740, same bezel and knobs even. So same thing, it fit great.

That's a 49 but "should" be the same dash.

I bought that one from Classic Car Stereos in California. Good service, even to remote northern BC!
Attachments
49 Custom Autosound 740.jpg (31.96 KB, 82 downloads)

1949 Chevrolet 3/4 Ton - Still Solid. Regular Driver
OT Vehicles:
1925 Hudson Brougham Super Six
1950 Chevrolet Styline (Parts)
1952 Canuck Pontiac Sedan Delivery (Well Underway)
1973 F250 4x4 Highboy
1977 F250 4x4 Lowboy