Hey sound-purists like me: My Fender Rumble 200 is rattling slightly. I reversed the speaker mounting hex screws so they go through the backside wood anchors first and then I installed 4 X .80mm (metric) nyloc nuts on the front all around the speaker mounting flange so nothing could be loose there. I removed the head and looked inside the cab--doesn't look like anything loose, glue still good and intact to adjacent strips etc. Amp head mounting screws good and tight as much as I dare without stripping. Yet I can stop the rattle if someone is actually sitting on top of the cab (putting weight down on top). Any ideas on what else to look for? Not loud, but any rattle is VERBOTEN in my world !