If you are not married to the design of a pair of jumprings on the
bail and a matching pair on the bezel, then maybe a design change
would help; you would still get the free motion you seek.
First, solder the jumprings to the bail. Without the mass of the
pendant interfering with your setup, it will be a lot easier to get
those on right.
Then, solder an upsidedown U to the back of the pendant, but now it
has to be threaded through the bail’s jumprings. (Ah, I have not
seen your design, so I don’t know if you have metal on the back of
the pendant that can support the legs of the U.) But if your design
gives the legs support, then you can set up your solder so the bail
puts no pressure on the U, and the legs of the U are flat while you
solder. This will make things a lot simpler, not having pressure
introduced from nearby parts.
I realize a written description can be confusing. If you would like,
contact me offline and I’ll send a drawing of what I mean. Sometimes
there’s nothing better than a picture!
Hold on, I just had another thought… get the jumprings soldered on
to both the bail and bezel. However, on one set of JR they are not
attached at the seam line. Let’s say it’s the bezel JR - holding the
bezel upright, facing to the left, and you looking from the side,
you will see the JR soldered at the 6 oclock position and the JR
seams at the 3 oclock position. Once all four JR are attached evenly,
gently open the bezel JR and thread the bail JR into place, and close
the bezel JR.
Now set up your soldering support and 3rd hand so the closed seams
are pointed up and the bail is rotated out of the way. Pick solder
the JR closed.
I remember when I used to think I had to kill three or four birds
with one stone (four jumprings interlinked and in place on bezel and
bail and soldered in place in one operation). Now I break things down
to take more steps, but it makes each step simpler and more likely to