Running "Flash_Shockwave_Full.exe /S" initiates a silent install with for Flash 6 and Shockwave 8.5.
Extracting Flash_Shockwave_Full.exe with PowerArchiver reveals:
INSTALL FLASH PLAYER 6 AX.EXE
INSTALL FLASH PLAYER 6.EXE
Should you need to install just Flash Player 6 (Active X version), Flash Player 6, or Shockwave; you can run the extracted installers individually. Though not documenation seems to be available, I found that the following switches work:
Silent install for Flash Player AX (Flash Player Active X):