On old motors, unless you are aiming for an "as new" restoration, it's always worth just being pragmatic.
What I couldn't quite tell though is that if this just a rectifier (I see both the word regulator & rectifier used on the part number) , then 15-16 volts is common and you don't have a problem.
The amp output from the stators on old carbed motors is pretty low at the best of times and it just fizzes the battery a little.
And even the ones "back in the day" with a regulator was a simple setup - just a zener diode and a heatsink I think.
Unlike modern stuff that has proper alternators & regulators owing to their much greater electrical needs.