Thank you Michael.
I have been unable to twist or warp a Planar rounded rectangle derived from a NON-Solid rounded rectangle, after several dozen tries.
Cannot seem to get rid of the extra control points.

BUT, Starting with a SOLID rectangle, was able to create the chain link, as follows.
1. Create SOLID rectangle 60 x 30 in front view. Show points.
2. Create 2 180 degree arcs with 15 mm radius, to round solid rectangle. Show points.
3. Trim the solid rectangle with the 2 arcs and select and delete the corners.
4. Select and delete the 2 arcs.
5. Select right 2 control points, rotate, select center of rotation at center right, and click on x axis in right view, and drag 90 degrees,
to form the curved plane "bowtie".
6. Hi-Lite the "bowtie", and select the six edge segments, and join them.
7. Hi-Lite "bowtie", not edges, and delete.
8. Draw 5 mm radius circle, for profile, and sweep edge rail.
9. Delete profile circle and rail.

Ended up with several circles on the chain link... because ?...