Is the cylinder considered an integral part of the revolver?
As I read the law, it's irrelevant. IANAL, but as far as I can tell, it doesn't matter what the LCAFD is or isn't attached to, nor how easy or difficult it is to remove and replace; if it's an LCAFD, it's regulated, end of story.
The good news- if you can call it that- is that the LCAFD regulations have a "Curio or Relic" (or
, not and!) exception for units over 50 years old, so regardless of how the regulation is finally enacted, pre-1963 rimfire 8-9 shot H&R's, High Standards, etc. should still be legal to bring into NY and won't require registration.