@11C1P
Did you have luck with this? Thinking about attempting this as well. I think I have some older version that has a longer tail on the back than the pictures you attached. Looking at mine side by side with a mil spec that's already SS cut, the left side looks really close already to what's required, just have to fit it to match (finding the right "line" from the trigger pin to use so it's the same level as the mil spec is hard), and cut the right side, which wouldn't take much.
If yours looks like the above pictures, it may not work, since it's a shorter tail. This is from memory (looked at this a bit ago and got distracted with other things). I'll try to snap some pictures of my trigger shoe to see if it looks the same as the above or if it is in fact longer.