If all you are after is the internal lock tumbler most locksmiths can fit one for you if you take the handle, or door lock key fitting in to them. Will probably mean you have an extra key on your ring. I had the same problem with my OKA and apart from 3 different keys (L and R door and ignition) they were done satisfactorily while I waited. Smaller blokes might have to order the tumbler in but most big operators should have something suitable in stock.
The following user(s) said Thank You: cobbadog, MR G
Last time I got anything like this done, the locksmith called the middle bit a "plug". Half of the pins are in it, the other half in the outer part. It has been quite a while, hope I got that right. The pins are readily available no problems. I think the Dodges have a different blank between the doors and ignition, though. My 1979 300 does and it's definitely original.
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