Key-binding without minor mode!

[Phillip Lord]

I am trying to find what a keybinding would have been if a minor mode
had not been active, by switching the minor mode off with a let binding.
But I don't know how to find the keybinding. I have tried...

(key-binding (char-to-string last-command-event))

Works quite nicely keys such alphabetical keys, but fails for return 
which return a symbol.


I've also tried 

(key-binding (this-command-keys))
(key-binding (this-command-keys-vector))

and also sorts of other alternatives.

I'd appreciate any help!

Phil