Warren in Lancaster, PA
What could be useful today would be for someone to describe what the Irion factory did. Here was a modern factory putting product out the door with a lot of hand tool work. Their techniques would have been efficient and reliable and in a setting and with tools more resembling our shops.

I have been in the old Irion shop in Christiana. They had a large bench room with partitions for about 10 guys along the walls with a large central isle, and a large machine room in the back. I am sure they used machinery to make mortises, but I don't remember specifics. Their idea was to make something by machine and then go back and cover all their tracks with hand work. I know six guys who worked there; I have done turning and carving for two of them.

What would be practical for someone needing to make a mortise would be to
ask any of the modern Period Furniture makers.

Which is what you did on July 10 2012 when you emailed me about making mortises. I wrote back five paragraphs. You tried it and thanked me.