I actually believe the lifts or at least close to them, with some caveats. They were never put together as a meet total, so not official. From what I remember, the bench was an exhibition gym type bench with the wide collar to collar grip that would be illegal now, but fine in the early days of lifting. So it probably was ugly by today's standard.
In early 1957 we can find an Odd Lift/Powerlifting contest report with the following numbers -
Bench 410, Squat 460, Curl 170. For those wondering, most older contests didn't use the deadlift, and instead went with the curl in its place.
Could the numbers jump from those 1957 ones to the ones claimed in later in the 1972 article? Perhaps, that's a lot of years, and Bruno did have some big fluctuations in size.
Just cause I kinda like the picture -
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