Having trouble with lofted feature

Hi friends,

I'm trying to model a scrolled cap rail for an intricate railing system I'm working on. The railing starts as an extruded pattern and ends up in a square. I've attached the model here.

The first sketch is Railing profile, there are two guide curve sketches, and then a second railing profile which is the rectangular pattern I want it to morph into.

What's the best way to do this? Surfaces? lofted boss/base? I've never done something quite like this before. Do I need additional guide curves? Additional sketches in between?

Thanks for your help

SolidworksSurfacing