Just a side note - what I like about this particular shape and size of ring is that it totally covers the area where the original gasket went. No matter what I did to try and clean the pontoon and tube, I could not restore it to my satisfaction. So this covers it and to my eye, looks like it might as well have come from the factory (though I know the originals looked a bit different).
The install, to answer the question in previous post, is very easy.
You DO NOT have to take anything apart.
Just clean the area, carefully slice the gasket with a blade so it can be expanded and put around the tube, then use adhesive to glue to the pontoon portion so it contours right to the pontoon shape. The cut side of the gasket should face into the corner where you would never see it.
There is room for improvement in terms of texture and exact shape, but again, hoping that Rob can improve on this so the community finally has a super strong replacement for this. I have always thought this is one of the worst looking parts of the engine area once the originals deteriorate.