Very cool. I just replaced my seat post due to clamp breakage. I generally try to get my seat as far back as possible because my frame is small.

I didn't try it, but is it possible to install a modern seat post with the clamp on top in a forward and also a backward direction to get more range of adjustment?

Also, a couple of positives for those old style seat posts. No clamp to break. And if the top of your seat tube is buggered, you can stick the seat post in upside down to help work things out until you can get it in the right way.