I wouldn't fuss with riveting, a lot of times the factory couldn't get it right. One example would be the radius arm brackets found on Ford F150s of the 90s. They were poorly riveted and the brackets walked back and forth causing bad effects with steering. Agree with the other poster, bolt it with some grade 8 Fasteners nut and lockwasher and you know it will be tight.

1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration