Check to see if the sear is case hardened or through hardened.
If soft steel under a couple .000" of glass hard surface anywhere on it,,re-case harden.
I use Kasenite for years and it works fine. I'm sure the other products do to.
If they're through hardened,,and you don't know what type of steel in this instance,,water or oil hardening. Quench in water with a slick of oil on the top of the water.
It'll in most every instance harden the steel so you don't have to repeat the operation if you choose the wrong medium.
I'd anneal them first and do any rework on them necessary (or not).
Wether the annealing is or is not advantageous to the re-hardening/tempering that's to follow is for the real experts to say. I always figured it was and did it that way.
Temps sound OK to me as we're just guessing at what the stuff is anyway. I'd draw them so that a new, fine cut file would just barely cut the sear.
Having the kiln sure helps.
No need to prolong the tempering heat soak.
