Sounds about right. I think they got rid of the SP8 and 9 grades early on, and then the SP6 and 7 later. The SP5 must have gone away in the late 80s?
I always like to tell folks I was in the brown boot Army. Depending on foot size, some guys were issued brown boots with a bottle of black dye in Sept 61 at Ft. Knox. I got black boots. We also had the M1. They were kept in locked racks in the middle of the barracks. I got an M1 thumb near the last day of basic training. Trained on the M48 during Armor AIT and we each got to drive the brand new M60 for about a half mile. My first Bn Cdr. in Munich wore a 3rd ID patch on his right sleeve and had been a POW in WWII. I ended up in the Bn Commo Platoon and my Platoon Sgt. had served with Elvis on his previous Germany tour. He had nothing but good things to say about Elvis' soldiering ability.
Well, brown boot Army? With the ACU, we are back in brown boots now. All patches, rank, name tags, etc., are stuck on with Velcro. The bad thing, is that the Velcro will pick up all threads or other cloth in the wash and make it hard to keep the stuff on the uniforms.