I’ve seen “soft solder” used. This is a lead based solder that
contains a small amount of silver and has a very low melting
point and results in a bright finish.
I hammer the round (about 16 gauge) solder flat and cut it in
small pallions with my shears. Using a very cool flame and
"Tix" flux, apply a small pallion of solder to the outside of
each piece of tubing ( after it is assembled in place), flux, and
solder. If done properly, you should be able to just put the
piece in the cleaner, steam it and sell it.
As a goldsmith, I would much rather see the rivets being used.
The drawback to the solder is it will contaminate the gold and
the ring would contaminate the pickle if it were to be sized
because of the lead content in the solder
Wendy Newman at @Wendy_Newman