Finally getting around to cleaning up the bearing edges on my Slingerland bass drum.

It's needed even more than the usual Slingerland 1/16" to get the reso side coplanar, and now I have this flat bearing edge.

I've gone through the process on about a dozen cheap rescue drums, and the method I've settled into with them is a roundover on the outside and a 45-degree on the inside, done on my router table, and then smoothed out by hand sanding.

I have some really nice-sounding cheap drums from this.

However, this is my vintage Slingerland bass drum, and I'm concerned about screwing up.

I don't think I can just cut an inside bevel, because the inside profile isn't a flat 30 or 40 degree bevel, it's a convex curve.

With vintage bearing edges in the past, I've flattened them and then restored the edge with hand sanding, but I think in this case, the flat spot is too wide in some places for that. It might work, but I want to know if there's a better way.

Experience? Ideas?