Here are the four installers for the Stuffit Expander versions mentioned above in DSK format:

Stuffit Expander 4.0.1:

http://sharebee.com/5961e690

Stuffit Expander 4.5:

http://sharebee.com/17284f01

Stuffit Expander 5.1.3:

http://sharebee.com/98f6cb3b

Stuffit Expander 5.5:

http://sharebee.com/e08f6dff

Figured someone might find them useful for something.