What's old is new again...Pinion's great grandpa

I happened to stumble upon this "restoring a bike" video.

Not much talking in it, but it seems to be a *two speed bottom bracket*
bike. I had never heard of such a thing...on this group or anywhere.

https://www.youtube.com/watch?v=SUi0PMG503g

The gearbox does not really make an appearaance until the "assembly" phase
of the video.

My mind immediately jumps to: How about pairing it with a two-speed rear hub
for a total of four speeds or a three speed and on and on.

I am very curious if anyone is familiar with this beast asto what the
ratios would be...direct drive, no doubt, and....?

pH in Aptos