Just found these today, sent off for from Negativland around 2000 – their Zapped! (Zappa tribute) Over The Edge 5 hr radio show, personally dubbed, written & stickered on 3 TDK cassettes – not on any discography, I think they’d dub any show for you for a fee back then via their website. Luckily, through the power of the internet, you can listen to this and many more shows from their huge run (1981-2015 I believe) via the Internet Archive.
Seriously, there are so many show up there you many never need to listen to anything else ever again.