if, after pulling the valve body, you can see burn marks, or heat discoloration, then the trans will have to be pulled and gone thru. Judging from what you've disclosed already, you might be better off just pulling the trans, and going thru it, again, anyway. It sounds like it was a slap-dash job from the "rebuilder" from the get-go. Document what you see and do, take plenty of pics. If it's as bad as you say, you might want to post it on twitter.