seat post problem

[Chrome]

So this Higgins got an odd sized post, but I have a base for the seat that could fit into the frame putting the seat at nearly frame hieght, only problem is, it wont come out of its present post, Is there a way to get this out? through the bottom of the tube looks like a ring is securing it, was hoping to see a nut, is this a one-time clamp?

 

[MonsterMetal]

Yeah... My guess (and thats all it is, a guess) is that the upper cast chunk is swaged into the tube... making it a permanent/un-removable kinda deal.

 

[Chrome]

Yeah, I kinda thought so too, oh well, the search continues!