For the 04/12/93 show, I had hoped there was an audio version but I guess there's only a video recording
Actually, I'm pretty sure an audio bootleg exists of this show, because I remember ACoS from this show was included as a bonus track on an old silver CD bootleg (I think from the 1992/10/04 show), and it was much better sounding than the video of the same show, although I don't have that track in my collection now. However, as far as I know, the rest of that recording of the show never made it into circulation.
As for the 03/26/04 show, I thought there was a recording of JPs guitar solo from that night on the DTIFC release "A Sort Of Homecoming"?
I would have presumed there was a recording of it unless it came from MPs archive and that he is the only one who actually has the whole show. It would be really cool to see that show surface one day, especially since it has the final "The Killing Hand" performance.
Most of the DTIFC releases were from MP's archive, and the compilation that make up "A Sort of Homecoming" are all directly from him. In fact, IIRC, the fan clubs received it completely edited together - it wasn't as if MP gave them all the shows and someone in one of the fan clubs edited everything together.