Need to find part #136420 mulch cover. The current part # from sears will not fit. Has to be the old part #. I have tried everywhere I can think of and they keep telling me the revised part # will work but mine is a prior to 1994 model and it will not remotely fit. I can only use the 136420 cover as the deck has a huge opening which has to be covered. Anybody have a new or used one? Thanks Bobbyf