A link to a photo would help a lot. If I understand you properly, a
possible method would be to create the triple helix on a low melting
point core, form the whole to the required marquise shape, bend it to
create the ring and then heat it to melt the core out before
soldering it up.
You could use lead as the core, or, even better, Wood’s Metal (its
the stuff that melts in boiling water). Take care to not allow the
core to stick to the copper.
I hope this helps.
Regards, Gary Wooding