Amos is a name which I used to dislike but it has grown on me, I think it would fit well with your other childrens names
Ptolomy is a great sounding name, its a name I love but would never use,
Walter Victor Bernard and
Basil are middle names only to me
Otis I dont like the sound of
Albert though I like it was the name of my sisters first husband so I could never use it, if not for this connection it would be on my middle names list.
Cedric and
Cosmo- not really sure about these though