Bob, Leo posted a picture of the filler cap area on his engine, and it seems to be one of the pre-1982 low ones that had just a filler plug with no dipstick. Those ones are supposed to be filled to the brim - in fact if you drain them and then pour in the required 600 ml of oil, the oil reaches right to the top of the recess and you can't fit in any more. Just to be on the safe side though, I warned him that if he has a dipstick rather than just a filler plug, he must only fill it to the level mark on the dipstick.
