For anyone else fascinated by the key/quay thing...

Here the story is in the 1937 Esquire... with the Key spelling... 

https://classic.esquire.com/issue/19370101

And here more about the words...

https://www.grammarphobia.com/blog/2018/04/cay-key-quay.html#:~:text=%E2%80%9CQuay%E2%80%9D%20was%20originally%20pronounced%20KEE,say%20about%20%E2%80%9Cquay%E2%80%9D%20later.

I would guess a radio script would use "key" in any case to avoid the risk of actors pronouncing it more than one way. :-)

Bob by the Blueridge