Modeling "ribbon" handrail - unsure on right tool(s)

I am trying to model a handrail that as it reaches the bottom it wraps around in plan before flowing to a flat position under the stair.

The “ribbon” stays the same width throughout, my initial attempt does this but the result doesn’t look natural, I’ve added a sketch which exaggerates the intent.

I’m currently trying InterpCrvOnSrf on a smaller cylinder but wanted to hear if there were other tools (I’m stuck on R6.0 so subd is out) that might help me connect from the vertical position to the ribbon landing on the ground.

Is there a way to have a curve follow the combination of two curves in elevation/plan? Since I have an idea of what the curve should do in plan, and also elevation, what might the best route there be?

Earlier attempt: ribbon looks a bit like clay rather than something that falls like a fabric

Current:

Initial wrap around cylinder but bottom side of ribbon will flair out while top will drop and travel under stair