Ignition switch failure/now ignition tumbler saga

[Huppert, Eric]

Gentlemen,
 
Thansk for the previous input, especially Peter!
 
Got the assy out, obtained the replacement ign cyl (used) and tailshaft.
Tailshaft is the same style, but doesn't sit quite the same on my cyl assy
and won't work. Decided to use the other assy with my tumblers.
 
Attempted to change tumblers from old lock to new. The replacement cyl came
apart, but unable to get my original cyl to pull out of the housing. 
 
Took it to a locksmith, but they're unable to disassemble also. Know other
listers have gone this route, any BTDT? Tricks???
 
Will try another locksmith later if no definitive responses!
 
Thanks, Eric