Very recently purchased a 1965 F100, 352 w/3 spd, and am in the process of sorting things out and cleaning it up a bit. I did run into an unexpected problem when I removed the air cleaner. Ive not seen one like this and was wondering if anyone has an idea as to how to disassemble this thing to clean it? Special tool? Some old twist-off technique? Its not particularly grimy inside so I suspect no one has really added oil to it for some time.