I've always wanted to do one just for the look.
They can be tricky. I’ve done 3 or 4. The fork in my road is whether the hardening is done before or after attaching the half sole to the frizzen. If I pre-harden it’s very likely the quench will warp the half sole. If pre-hardened, then soft solder or (horrors) epoxy can be used to attach the half sole.
If the sole will be hardened after installation, then riveting works well, as does brazing. To braze in place I form the sole to fit closely then wire it in place with a brace of soft iron in the center of the valley of the frizzen face. I did this with real brass brazing (brass filings in the sandwich and sheet brass fed in the edges). Then once the braze flowed like water I quenched in water, pausing till the braze solidified but the steel was still in a red-orange range for hardening. Brass brazing flows at almost yellow color and solidifies above hardening temps for steel.
I got an edge crack (top right) but it added character. Great sparks. Old handsaw blade steel was used for the half sole.
Riveting will be more obvious (maybe a plus) and contact between frizzen and sole will be great, and hardening a piece of cake.
