Gary's absolutely right. You have to put the engine where it's supposed to go and fit the cowl to that. I just finished up a Funtana with a Saito 91. The 91 is a little bigger than some of the engines that fit in there but still works just fine. What works for me is to use a piece of acetate (clear plastic) and tape it to the side of the fuse. I just use a single piece of tape and it acts like a hinge. I then transfer the different points to the acetate with a sharpie and also mark the edge of the fuse. Then take the acetate off and add it to the cowl and tranfer the cut out points. I like to drill into the cowl and then use a tappered reamer to size up the holes to the size I need or make them big enough to get the cone sander for my dremel into the holes. Here's a couple of pictures but it really does look better in person.