Q: How do I combine several PS files into a single PDF file?

Create a new (text) file (called, for example, combined.ps) containing the following (``header''):


/prun { /mysave save def
        dup = flush
        clear cleardictstack
        mysave restore
} def
Append to this file the list of files you want to merge into a single PDF file, using the following syntax:
(/PATH/TO/FILE1.ps) prun
(/PATH/TO/FILE2.ps) prun
(/PATH/TO/FILE3.ps) prun
(replacing /PATH/TO/FILE with the appropriate path of course). You can list as many files as you want; they do not have to be in the same place or bear a number.

Then type distill combined.ps on the command line, and this will generate combined.pdf, which is what you wanted.