Thanks for all the tips guys... unfortunately I don't have a good picture of the broken part, but essentially the "active" side's handle broke off about 3/16" below the riveted joint.
Also, it would probably be good to point out that this SAK is a knock-off (China?) that I got with my dad a as a kid... I'm fixing it more for the sentimental value. I'm assuming that Victorinox won't fix something that isn't theirs.
At this point, I believe I have two options. (1) pay a jewelry/laser welder to tack on the broken section or (2) find a "donor" knife and do a swap out.
In the time of COVID, I feel like the responsible thing to do for "non-essential" work, such as this, would be option 2.
As always, I'm slowly learning, so any suggestions are welcome!