The thickness of the staves of the original lamp gently narrow from bottom to top.   Ordinarily, I would do that tapering prior to shaping the edge profile on the router table.   However, given how thin the stave would be at the top (and subject to a router table disaster), I cut the outer edge profile on full-thickness staves first, and left the tapering until now.

With the internally-facing edges still square, I marked a narrow taper on each side, starting just above where the staves join to 1/8" in from the edge at the tips.   Applying the taper at this point meant that I would have to reshape the already-routed outer profile, but that would be easily and safely done using hand tools.

A partially shaped stave on the left, full width one on the right.  Looking much better.

Once I was satisfied with the taper, I used a trim router with a 3/16" radius bit to round over the inside facing edges.  The small radius cutter won't stress the wood like the bit used for the outer edge profile.

I made sure to tape the areas I didn't want to hit with the router.  It's just a visual reminder to stop.

After routing, I started hand sanding with 120 grit to further shape the staves and remove router marks.

All rough sanded.  I might shape a little more, but I'll live with them in this state for a bit.   When it's nearer glue-up time, I'll decide if they need more shaping before final smoothing.

I'll leave the staves dry fitted while I work out the details for the shade.