Shorten (.shn) files and conversion

Many a moon ago, I traded and archived lots of live “bootleg” shows from many artists that I archived in Shorten .shn format. I’m sure at the time it seemed like a good idea, it was a lossless format but is now extinct. I am looking for a reputable converter from .shn format to any other newer format, preferably .flac. I have both Mac and Windows operating systems. Hope someone can help out.

The Wikipedia page has examples of using ffmpeg to convert the fies to FLAC:

On a Mac I’d say give XLD a try. I have been using this app widely for format conversions and basic tagging. On the referred website it says that it does recognize shorten files, but only shorten V3.