yes
you can add extra timber below, either square stock, or cut at an angle to move the line in with the ceiling.
if it's a period house, you could add some "fiddley bits" such as corbels for decoration.
I did something similar when I replaced my entire banister and used griffin and very thin MDF to hide butchered mess. any seams can be covered with half round moulding to hide them.
Presumably you're not leaving the stairs like that when not working?
a timber handrail lashed with rope will stop a nasty fall
