On the breather element that slips over the pony engine oil fill tube it looks like there might of been at one time wire mesh filler that was supposed to be inside of it to help with any oil blow-by. The breather looks just like one off of a d2 3j1. Part number 4b11. Mine is completely hollow between a set of baffled plates between the top and bottom. Just wondered if I needed to fill that guy up with something or if mine was correct.