The best advice I can give is to make sure you have the engagement
ring when you put the guards back together. You can hold the rings
together with inside ring holding tweezers or with binding wire.
Once the first support wire is soldered on you can remove the center
ring and add the other wires, checking to make sure the rings
haven't misaligned in the process. I know customers don't like to
leave engagement rings, so I charged more when I had a customer who
wouldn't leave all three. The added fee usually persuaded them to
leave it but it also helped just explaining that we couldn't ensure
a proper fit if we didn't have the set.
Now, about those pesky baguettes and the steamer. Take an empty
plastic gallon sized distilled water or milk jug and cut out a
quarter section from it on the opposite side from the handle. Don't
cut too low, just low enough to give you clearance for your tweezers
and the item you hold. Place the jug so the steamer nozzle goes
through the pour spout and sits just next to the steamer. You have
now created a shield that will catch those pesky stones. Pour out
excess water that accumulates to eliminate splash back.
Good luck finding your baguette,