The numbers on the Angle Lever Cam and Tool Head, as well as the numbers on the Bronze primer casting and the steel base are assembly numbers. In both cases, they were parts that were hand fitted, then went on for further processing. The numbers allowed the parts to be re-matched with their mates during final assembly. On machines made in the early 30's, the numbers on all four parts matched. On very early machines, the #45 Primer Punch Rocker Arm was stamped with the same number as the steel base.
In the case of the Angle Lever Cam, after it was fitted to the tool head, it went on to be hardened. You can use an angle lever cam with a different or No number, but it will likely require some tuning.
The numbers were reused many times. The highest number I have seen is 115, which probably means there were at least 115 machines in that batch(?). Star also used letter stamps.
Bruce Williams