There's a product called Black Magic that will do the trick. Used to be sold by Brownell's, likely still is. One caveat-- when you put a tiny drop on that gold bead and touch it to the sight blade, be danged sure it's positioned just right because it will adhere RIGHT NOW and only heat (as in a deft touch with a propane torch) will dislodge it. I have a 12 ga. shotgun that I glued rifle sights on a dozen years ago, and right now if I took a hammer to those sights they would break before the glue gave up.

__________________
Pisgah