I felt a bit the same way a few months back when I had a mysterious oil issue on my DOHC 450 engine after a complete overhaul during my build. I struggled with it from many directions and at the time, I felt I wasn't getting as much help here as I'd hoped for but the truth is, mine was a strange and unique problem and all the advice I got was the usual, general stuff that I'd already double and triple checked and was sure was okay. In retrospect, it would have been next to impossible for someone not in my garage with me and looking at all that I looked at over 3 cam follower/cam bearing disassemblies to see or think of something that I missed - and in the end, I'm pretty sure it really was something I missed. Miracles don't usually happen from the freely-offered information given here, but there are daily successes from the knowledge base here and it's always given in good faith and with a real interest in helping someone get through the moments that are difficult for them. Yours may well be like mine was... and since you are the only one who can truly see what has been done, it might take you grinding it out - much as I had to - until that comes to light. I absolutely know the feeling... and if there was something I/we could tell you that would solve it for you, we absolutely would.