So, the files are still on Amiga format discs, then?^^^Wouldn't he have to have a means to read the disks, as that's what the problem appears to be.
Correct. I had "cross-DOS" on my Amiga to bring all the still images (I think Corel read .IFF files to convert them to JPGs), and it let me convert the Caligari meshes because there was a version for PC (TrueSpace). But there was no conversion for .ANIM format to anything PC-readable.
The files on disk, and on a removeable drive, are up in the attic. I doubt the media is in very good shape.
I have 5.25" Atari floppies from 1985 that still read fine, so you might be pleasantly surprised.