If I use sprue to rig my builds (and I tend to use both sprue and stainless) I make sure the build is
completely finished before I attach any rigging.
I've been using Elmer's white glue lately. It's especially good with super-thin sprue as it doesn't heat up the fragile plastic like CA or cement. It also gives one the option to remove the rigging piece and reposition, remeasure, etc...if needed.
Good luck, and happy rigging! I can't wait to see the results!
From the Factory on the hill,
John