USE bar ends were designed to go with USE bars. You'll have to be very handy with a drill to fit them to a different bar, otherwise they'll just end up wonky.
(I've got a box full of them in my loft - black stubbies, navy stubbies, navy ski bends, one purple stubby. Just one spare red bar. Bar and black stubbies not for sale. Others - some incomplete hardware, purple free to good home)