Personally for downloads I much prefer mp3 . Old radio shows do not need to be flac or wav which is overkill given the quality and response of the original recordings. Any good 128kbps mp3 is more than adequate for excellent quality not to mention the smaller file size that uploads much faster that a fat hulking wav or flac file.
For my radio stations I have to use wav files but when I compare a 1940s-1960s song mp3 320kbps  vs wav....there's not a grain of difference in the audio. So convert them to mp3 and save