Good job. As bad as it looks, I don't see a problem at all, it's fixable. The great work you did already is proof. Stainless is very malleable. The trigger guard is not an area needing strength nor any of the other locations. And there's plenty of thickness on the back strap.

Micro welding would be the quickest. All the metal is still there it just needs to be heated to flow and level it. Then dress it down which will be minimal. I would fix the back strap as well, but that's just me. I'm not a fan of stippling. If your friend that welds is not enthused about doing it, I can recommend two well known micro welders that specialize in micro welding gun repairs. It's amazing what they can fix. You could send them a photo and get an idea of the cost, you may be surprised.

Good luck with your restoration,

__________________
Jim
S&WCA #819