psroff was part of the Transcript FWIW. It was the moral equi to the UCB command vtroff which did the call to troff -t ... | vcat
BTW: I just peeked, on Disk 4 of Kirk's archives are the source to both ditroff and Adobe's transcript in the 'local' directory.
I would suggest starting with transcript, copying to your system and typing 'make'
That will allow the BSD troff stuff to 'just work' us pscat/psroff/enscript et al.
This is how most sites that did not spring for a ditroff license worked with their Apple Laserwriters or later PS printers.
Then if you want to do the same thing with ditroff, that should 'just compile' and build and you replace troff with ditroff.