Hi Gary, so some boolean union steps might go something like this - start with a block in the middle (maybe a bit longer than what is shown here actually, but you get the idea):



Then extrude these 2 parts out to make separate pieces for them:



Then boolean union those 3 pieces together, and then cut the hole with boolean difference:



These steps could be easier to control the shapes since you are building each of those end pieces as a whole individual piece, so you can focus a lot of attention on making the curves that are being extruded there to be high quality, like all curves tangent to one another, not any more segments than needed (like make 1 line and not 2 or 3 little lines where you only need 1, etc...).

It's a bit easier to focus on initial curve quality when building one component at a time like that.

- Michael