Horton 6 " 34C chuck

[Clockman44]

I am trying to take apart a Horton 6" 34C chuck on my Sheldon 10" lathe. This thing comes apart different than those I see on you tube. It is stuck and I've tried everything that I know to take it apart. It has a rim that slides down into the chuck and I am soaking it in mineral spirits now to see if it will help loosen it. I got one of the cups that tighten the gibbs out,but the other two don't want to come out. I was hoping I could find a video on this, but to no avail. Has anyone out there experienced this problem. If you got any ideas, please let me know....thanks, Tommy..(Clockman 44)