I mention Gayle ( you said Gary) because you said the A1200 IDE does not work, you can check that there is a signal there with just a cheapo logic analyser that will show if there is a signal present, Amiga`s are weird they can fry anything PMSL, does the Gayle chip get hot ?
here is a video of me checking the CS signal on an A600 gayle, ignore the video quality my camera is C**p
https://mega.nz/file/ExR0AazK#M9NAZ1...7UaSygGxyG2oNg