Sorry to be the spectre at the feast but even if you used a low temperature silver solder such as Easyflo or Easyflo No.2 (liquidus 630ºC & 617ºC) on the ring which is in all probability a case hardened component I reckon you’ve pretty much ruined it.
Such parts are heat treated to provide the hardest possible bearing surface and as such are unlikely to have a post hardening treatment at much more than 250ºC, more a stress relieving exercise than tempering. Heating to silver soldering temperature will seriously compromise the crystal structure of the metal, which in turn will lead to early failure.
On a slightly different tack and as per Radcool’s warning, my Squirrel’s flywheels have also seen fretting in the gland slots and someone in the past had tried a correction with dubious results. In an effort to square the slot up and provide a harder surface for the gland tongue to bear against I machined a hole down the side of the slot and pressed in a standard needle roller. For the sake of belt-and-braces I also used a drop of high strength Loctite and punch locked the end of the hole to make sure the needle couldn’t move. It remains to see how effective this repair will be over time but at least there is now a hard bearing surface that is square to the axis.
