I do have all of Osbornes assembly manuals, but as I stated I wasnt able to find a diagram that showed that bolt. Now I have been known to be blind when it comes to looking for things, just ask my ex. I also looked at the hardware listing in the library section and in looking up what I thought might be the correct bolt and cross referencing it with AMK I wasnt successful in my search. That is why I asked the experts. On a good note, I was lying in bed thinking about why the bolt was missing and it dawned on me that it might still be on my old water pump. And lo and behold this morning I checked and there it is. So all is good now.