1screech,
There are so many different Japanese machines out there it's almost impossible to tell one from another without photos.
Could you post the pics you have so we can get an idea of what a 2448 looks like? I checked with Relics and they don't have a manual for it. So I'm lost.
I also have run across machines that are overly complex. They can give a person nightmares.
I can't say anything about Nelco machines as I've not yet had the pleasure to meet one. It will happen eventually.
Joe