It gave me a "fingerprint" of BB85CC1E5D18B9E292G56G18H5957R217G44F (I made that up but that's how it looks, no special characters, only numbers & capital letters).
It says the key ID is R217G44F, which is the last 8 characters.
So all I do is give gribble the last 16 characters as the key ID?
Yes.