As you might understand, iboats frowns on us posting hyperlinks to other boating/parts sites. That said, if you Google around a bit looking for Mercury KE4 parts, you should come up with a few possibilities.
The only cowling on your motor is the lower. The upper you refer to is the gas tank, and they were generally left in place as they tended to not run well without them. As for finding a replacement, they are out there. The turn up on eBay from time to time - be very sure you know what you're bidding on as many old parts sellers don't know what they have and many of the cowls look similar, but won't fit from one model to the next. For example, a cowling off a 7.5hp KG4 will NOT fit a 7.5hp KE4. And a 7.5hp Mark 7 cowling may fit your motor, but the lower edge cutout on the exhaust side may leave gaps due to the Mark 7 exhaust manifold being a bit larger. On the bright side, Mercury made a lot of them, and one is bound to turn up sooner or later. Although, what usually happens is you end up buying a parts motor to get what you need, then you have two, which will become four, and so on. As diseases go, there could certainly be worse....
