Reduce the drawing to the bottom only, as I did before.
Highlight the edge (only - not the enclosed face) of the outer circle. Open the Entity Info window (R click on the edge) and change the number of segments. Try 96.
SU won’t let you create very small edges - that’s why you couldn’t use 200 or 300 earlier.
Delete the small ‘circles’ (mostly polygons) and redraw one with the Circle tool, the right size but with fewer segments - try 12.
Array that circle in the original spacing, using Move/Copy (press m, then tap Ctrl - or Option on Mac to toggle Copy on.Watch to get the little + sign on the Move tool icon). Move one copy the right distance and direction (use an arrow key to force the move on green or red axis).
Type 5x (or use a different number than 5) to repeat the copy 5 times.
Select the row you’ve just made and copy that as many times as you need. Delete any extra, or add missing.
THEN push pull the whole face 60mm to get your smoother outside, simpler inside, solid again.