I bought the 1996 Shop Manual and the 1996 Shop Manual Supplement when I bought my new GTX in 1996. I have always found it to be super confusing to use because the main shop manual talks about everything but GTX’s, while the Supplement doesn’t seem to have complete info on the GTX.
I finally stumbled across the 1997 Shop Manual at Miki’s Link and found it to be much more useful for my 1996 GTX because the GTX information is complete and coherent.