hey good job on clutch-lever perch repair! I usually add extra metal powders to mix for additional machining strength. If threads doesn't hold, you'll find that adjuster lockring is all you need, but it may creep over time if adjuster's not tight inside hole. You can always use steel case-saver insert for VW Bug!
https://socalautoparts.com/product/c...rt-12mm-x-8mm/
After threading M12 hole, use red Loctite to bond, then cut cable-slot. Be sure to round off sharp metal teeth at edge of slot, it'll grind away at your cable until it snaps. This is due to cable being moved in an arc due to rotation of lever around pivot. Some MTB levers are pretty trick with cam mechanism to pull cable linearly.