I got this to work on Leopard and Tiger for Quark 7:
tell document 1
set properties of print setup to {bleed:"0.125", etc}
set output setup of print setup to "Composite CMYK and Spot"
print page 1 PostScript file (alias.ps) as unicode text
end tell
I could not set the output setup within the properties line, it had to be on its own.