Hi! I'm quite new to solidworks - I've managed to make the object I'm after up to this point but am now completely stuck! I want to create a curved surface joining the outside of the dome shell to the top of the base (It will make the printed object easier to pull out of a sand mould for casting). My initial idea was to create a 3 point arc from the shell to the base and revolve the extrusion from the arcs on either side and extrude arcs straight from the linear sides but there is no fixed point to make the arc coincident in the dome shell... Any ideas how I can achieve this?

Any help would be very much appreciated! I've been trying to figure it out for hours!!