Links to the official web pages for drivers download for Ricoh printers:

MP C3004/C3504 series (cascadia, challenger)
http://support.ricoh.com/bb/html/dr_ut_e/rc3/model/mpc3004/mpc3004.htm

MP C401SP/C401SRSP (agulhas, walden, adm)
http://support.ricoh.com/bb/html/dr_ut_e/re1/model/mpc401/mpc401.htm

MP C300/C400 (laurentian)
http://support.ricoh.com/bb/html/dr_ut_e/apc/model/mpc30/mpc30.htm