Hi.
Welcome back.
This is a thought only, open to discussion or ridicule, viewed from a carpenters point of view.
Here goes.
Reverse B. Quite happily churning out pennies. It's getting on a bit and a small die crack appears.
You need to prolong its life for a while because the new reverse C die isn't quite ready.
To prevent the crack traveling further, you drill a small hole just in front of it. This will stall the cracks line of travel. Not prevent it. Just stall it.
A perfectly round hole. Or dot.
Fill the crack in as an added form of strength, clean it off and away you go again. A dot penny.
Hole fills with grease and gunk and becomes the shadow of the dot. You can see it on some 97's in the right light. Can't feel it as raised, but you can make out where it is.
After a while the die crack continues its travel. The dot hole deforms as a result and you're left with Jerry's penny.
But you've achieved your aim. You've prolonged the life of the die. The new reverse C is now ready and production resumes as before.
I'm sure that this theory is full of faults and assumptions but it's food for thought.
Bob.