On Thu, 22 Dec 2016 00:55:50 -0500, Steve W. advised:

I won't patch a sidewall on a passenger vehicle but on something like a
tractor, loader or skidder I don't have a problem using a chunk of live
rubber and vulcanizing it in, I've even stitched some together and
patched them. Toss a tube in to hold the air if needed.

I thought nobody patched sidewalls, but this article says it's pretty
common to cut out a section of sidewall and to vulcanize rubber to patch
them in truck tire carcasses.

Knowing what not to repair
http://www.moderntiredealer.com/arti...-not-to-repair
"injuries in the crown area that are larger than 3/8 of an inch as well as
those located in the shoulder and sidewall must receive a section repair
that requires additional time, tools and equipment not typically found in
the average commercial tire dealership. Section repairs are most commonly
associated with retread plants where the technicians are trained to use
special tools to remove the damage and fill the void with raw rubber so it
can be cured in a press or chamber. A large reinforced repair unit is also
installed on the innerliner of the tire and the tread design is regrooved
after the raw rubber has cured."

An interesting sidelight in that article is this quote about carbide bits:
"You?ll never find the words ?hand-reamer? or ?drill bit? in any credible
tire repair resource. A carbide cutter is specially designed to cut the
damaged steel belt and body cables flush with the surrounding rubber. This
stabilizes the area so the void can be filled with a cured rubber insert"

So the three tools I will get are the following:
1. Carbide bit (which cuts the steel belt and body cables flush)
2. Cone grinder bit (which has a better shape than a wire brush)
3. Flexible knife (which is better than the dremel disc cutter)

I'm learning as I analyze all the steps.
Some day I will teach others, perhaps at the adult schools nearby.