What on earth is that piece of rusty metal that has been Horribly melted onto your frame tubes
... don't learn to weld things onto a motorcycle frame if they can be bolted to the frame. That weld has so little penetration it wouldn't hold anything, the attempt did more damage then good. Is it a battery box? The battery box is ideally rubber mounted to begin with.
and by the way, you couldn't fit a single carb on that if you tried, the pressed metal frame member is completely in the way.