The sight tracker being the big lug at 12 o'clock? That's just welded on and not part of the machining? Yikes!
"welded" with epoxy or brazed together? If the epoxy breaks loose and you score a Delta with the lug
....you could always just epoxy it back on. There's some trick epoxies that are made for contant vibration environments...they cure with a little ductile-ness (?) instead of "strong as a rock right up until it cracks" hardness. But I don't know...
It's not the shear strength...it's the fatigue that get's these GBBs.