Those ' Dingbats' were originally called 'Feet' in the die cutting trade.
Used on roll dies to allow the die impression to walk onto the surface first before the initial letter/number impression.
That meant for the 'Foot/Dingbat' to establish the impression depth for the lettering/numbers to follow.
It kept the very first letter/number(s) from being extremely deep impressions while the continued roll marking would then lighten up in depth as more of the character(s) was in contact.
There are only a very limited amt of actual roll die characters in contact with the surface being imprinted as it's an tangent. Plus a smaller dia roll die can limit the contact even more making impression dept easily deeper on first contact.
The 'Foor/Dingbat' at the end of the impression serves the same purpose. It keeps the final character or two from being impressed too deeply. The Foot allows the die impression the walk off of the surface last and will take the final pressure, not the last character or two.
It all just makes for a nicer looking roll marking.
It was also used in lining up the roll die on the marking apparatus as well. The 'Foot' is easiest to see and center visually with a guide line to line the die up.
Once the machine was set and locked in, the 'Foot' did the job described above.
Back when, roll die marking 'machines' were mostly a hand operation machine.
Place the part in the machine, Lock in place in the pre-set guides and then pull the roll die over the part to mark it.
Do not back the die up over the part,,it will never exactly match the original 'pull' in the same place. That's where you once in a while see a double strike. They get by QC and out the door. It's just a factory.
Forward to today,,the Dingbats on dies are not really needed.
Roll dies are machine controlled in their positioning and application.
The pressure upon the metal is constant so there is little real need of the small foot to avoid deeper depth imprint at the beginning and end of roll marked lines.
Sometimes the marks are still used for classic looks.
Dies are just about all machine made now. A few hand cut dies are done still but to find someone still cutting them is rare, especially someone who will cut a roll die with a line of lettering/words/numbers.
Single stamp die cutters are still around, but the machines can do it quickly and that's where the industry goes and gets them.
At one time the engravers in the factorys spent much time cutting and re-cutting/sharpening stamps and dies.
Every marking on every tool, machine, tag, & firearm etc had to be done with a stamp or die. They were all hand cut dies and stamps.
A couple of the engravers ran side bisinesses of Stamp & Die Shop outside of the factorys they were employed by that specialized in just that.