Occasionally I download files with the MP3 extension that won't play
and on checking the file info in Winamp it shows the following:

Size: 5500139 bytes
Header found at: 4266 bytes
Length: 171 seconds
MPEG 1.0 layer 1
256kbit, 6586 frames
44100Hz Stereo
CRCs: No
Copyrighted: No
Original: No
Emphasis: 50/15 microsec

As you can see, they're actually MP1 files but even though Winamp is
supposed to be able to play MP1's, it won't play the files in
question.

Is there any way to fix/convert these files?