Thanks gentlemen.
Jeremy,
In the first picture above, you can see the rivet, actually a tenon, has been filed roughly to shape. It's sort of octagonal. I then took a bolster ( a piece of stock with a round hole in it) with the corresponding hole size and drove it over the tenon while the tenon was at a bright orange heat. The bolster smooths the tenon and forms a seat on the stand off ( the little hump that the tenon sits on). The bolster needs to be held at the desired angle that flows with the guard curve.
Keep in mind that this whole thing is small in mass. You have to work quickly, going to and from the vise, and have your tools laid out near at hand.
The next picture shows the tail fit over the tenon and bradded over. To brad it requires the entire piece to be heated evenly (medium to bright red), placed in a smooth jaw vise, and use very light accumulative blows with a small ball peen. (Don't even think about using your forging hammer.) This will take a few short heats.
With the tail held securely, you can refine the handle shape and straightness of the entire knife. Even, low red is good for this.
Thermo cycle. Never cool any parts of this type of knife in the slack tub. Just wait on it to cool.