904 Transmission Stopped Going Into Gear

One of the hardest parts of my job is figuring out what the last guy did wrong. Your band was destroyed and your thrust washers are weird. I would be finding out what caused those two things before I put it back. The valve body may have been reassembled incorrectly by the last guy and you might reassemble it the same way. I saw your pic of the valve body but I only saw large particles outside of the filter area. Most times vb disassembly isn't even necessary; the black sludgy stuff settled inside usually won't hurt it. I mostly only find bad valves in transes that have water in them. I wasn't suggesting the shift kit as an upgrade; but as one more step in avoiding troubleshooting after the fact.