Not following...thoughts on what? How to get the two separated or what caused the rust or something else?
I'd be cautious of side loading the gas tube to try and walk it off the gas block nipple....seems like the Type 2s need a tight fit for accuracy....at least on the Ms. Penetrating oil and trying to get it to turn even a bit might break it loose....you could try something soft like a wood dowel in one of the vent holes, though you'll have to pull the gas block off the bbl to get to those holes.
I don't think I've ever taken my Type 2 apart....can the end come out so you could knock the tube out from the inside?
I dunno...just brainstorming.