Welding on transmission

I'm working on a 2001 Hyundai Accent with the manual trans and the throwout bearing sleeve got cut off in a catastrophic failure of the throwout bearing and pressure plate. There is still about 1/2 inch attached and I was planning to grind it down enough to allow an aluminum pipe with the same outer diameter to slide over it then braze it to the housing. My question is do you think the high temps needed for brazing (700F) would damage the input shaft seal that is located directly behind it? Should I attempt to use JB weld instead?

Here is a picture of the damage
https://drive.google.com/file/d/1Vwbz5qG5vix5Mnso5xdIfviDZa-9Zi0O/view?usp=sharing