I think I understand what you're looking for ("creases" in the ripple; shell would have none). If these turn out NOT to be shell, would it be a waste of $$ to get them resoled and reconditioned?
(and sorry if this line is getting a little off-track with the thread theme)
FTFY - looks like calfskin creasing to me from here, but it is hard to say for certain w/o closeups. I did come across a pair of Florsheim saddles a while back that actually had shell vamps and a calfskin saddle. Thought that was bizzare.