I was able to find a Rev 1.01 LK204-25-PC display myself, and give it a quick test. Unfortunately, I can't seem to replicate the issue you're having. Much like Henry's experience 15 years ago, my display is working perfectly fine.
It may be that the display is victim to a 15 year old bug, or the display memory may have been wiped over the years. Unfortunately, all I can suggest is to order a newer display.
I guess there's no hope for me. I don't think it is memory related and more probably a manufacturing problem on some batch. I wish I replaced the unit back then.
Unless there's undocumented command that only Henry knows of that could solve the issue, I can't think of another test or command combination to have those large digit working on the module. The fact that I figured out how to use graph bar by setting the chars manually is at least something.
Maybe you can give me the values for the characters from the character set used to display the large digit and I'll implement the display function myself with the custom character command so I can finally see what the digits look like :) the only downside is that it will take cycles on the arduino instead of on the LCD module.
Thanks anyway. If I need some new modules one day, I'll definitely have a look at the new catalog.
Your replication is pretty on the spot.
I've drawn the large digits from 0-9 on one of our newer displays so you can see how each digit should look.
Hopefully this helps you sort out the rest of the digits.