I cross the grain lightly both directions when sanding these patterns. Then come back with the edger to clean up & feather out the lines from the drum. Follow that up with the U sand (4 head RO sander) to clean up the edger marks.My last house,built in the 1800's had the same pattern in the dining area.
I had the pleasure of refinishing it,mostly by hand sanding so I didn't cross the grain with the drum sander.
The same room had a built in wall length hutch,with leaded glass doors,bay shaped bevel glass mirrors,and beaded moldings.Everything,even the glass was painted over.
Took days to strip it all down but well worth it.In other rooms there were marble mantels,also painted over.
The window casing and trim there looks like it may clean up pretty good too.I'd be nice to see that saved from a coat of paint.