There`s a small, very small chance it was done,...no,,..change that, the person that screwed up the large hole, covered the hole and his tracks with the L arm. The lug holes are no doubt done with a jig and high speed drill. The add on`s to order, would be side stations with pneumatic drills or electric drill that have very high speeds too. That assures clean holes and longevity on the drill bit. Factory stuff. Those look done with a store bought low speed compared to commercial grade motor. I think the factory would plug the big hole or can the shell.
I hear you O. I feel the need to add that the 60's were odd as $h!te to say the least when it came to this sort of thing. I've seen enough 60's Ludwig + less (but enough) Rogers to know that anomalies did happen.
I've learned a couple valuable lessons : painting interiors done after drilling. + it's twin : if no paint is on or near drilled areas then it's possibly aftermarket addition. OR done by Rogers (in this case) after initial drilling. & it could be that a Roger's employee did the poor drilling and "covering up." If it the mutilation was done by the owner of the bass then he was pretty savvy to know that a different mount would cover the crime.
