I am trying to “fill” the triangular hole in this model. Is there a way to bring the edge out but narrow it to meet the point?
Do I understand correctly that you want that hole filled, but not to the bottom of the body. Only that top layer? What. I would do is add a plane by selecting the top surface and move it somewhat up. Then I would project the triangle edges on the plane and extrude it (more than neede to fille the hole). I would then push the new body into the triangular gap. Then I would use Replace surface to level the top surface of the new body with the existing top surface and the same for the bottom of the new body. Lastly you need a Union of the new body with the existing body and Bob’s your uncle. You could do this in without moving the plane upwards, working from the top of the surface of your existing body and extruding downward directly with the correct thickness. By default it would create a Union of that new shape with the existing body. Its aves a number of steps, but when it goas wrong it is more difficult to correct.
Here I sketched a triangle on the surface you want to fill. The dimensions don’t matter as it is basically a patch. I subtracted the patch from the original body(s) and used Replace Face to make it flush with the underside. After that you can do a Union to whatever surface works for you.
Thank you both!