Found on Victor C-14 Westinghouse WC-44 V-39 V-44 VMC-44 V-56 round top VMC-56 Round top V-80 V-81 VMC-81 V-83 V-110 Vendo 6-Case Vertical Cavalier CS-72 CS-96, CSS-64D, CSS-64E, CS-64E, VMC-27 VMC-33 VMC-33-3D VMC-72 VMC-88 and others.

3/8" shank size.  Sold individually so order as many as you need (4 per machine).  Do you need the mounting plates? See HP103A.