Baker "N" Grade Krupp in a 1907 advert: http://books.google.com/books?id=POUXAAA...els&f=false

Looks as "The Simplex" by Tobin also had a Krupp tube option - 1905 - http://books.google.com/books?id=SxgLAAA...els&f=false

Kind Regards,

Raimey
rse