big radial sidewall damage repair

[fitterski]

I found a used tire for $250, finished the fornt axle-build and stowed it just in time for winter. The rebuilt engine should emerge from the skunk-works in May.

 

[LouNY]

This outfit has tire boots and repair materials,
Patch Rubber Co. - Specialty Materials - Oval Boots
I used to get most of my repair materials from Blackjack tire repair but their website is not opening for me today.
I would'nt be afraid to use some of the glue tread products along with a large boot.
If you search for tire boots they are easy to find, a boot patch is designed to patch the carcass of a tire and has multiple plys with the tapered edges you will need inside the tire.

Edited to add;
here is an interesting repair on a tire