W108 250SE ignition barrel removal

[Tassie Tiger]

Hi,
My ignition key is occasionally jamming in the barrel. I have the older type of ignition lock assembly usung a single cut key.
I have tried to remove the barrel but cannot remove the chrome sleeve. Followed instructions by turning the key to position #1 but no luck.
I purchased a spare ignition assembly but it must be from an later W108 as it uses a double cut key and it won't fit on my steering column. The barrel on this was easy to remove. Hoping that I can exchange the locking barrel from one to the other.
How can I remove the older type of barrel and can the newer barrel be used in the older assembly?

Thanks,

Alex