www.ohmikron.com/index.php
Click on source-code PPT0106 (Yes, I know you have a PPT1006, bear with me)
Looking at the source code it appears that the output is a simple step-and-direction scheme (I was worried for a while that the PPT board was a "smart" interface with onboard step generation.)
The pins seem to be hard-coded, and can either be determined from here
www.ohmikron.com/templates/static/source/setup_c.html
Or by simply running the existing software setup utility and making notes.
Assuming that they used the same driver chip on all their drives, it looks like 2uS (2000nS) step and space timing would work, but in practice you might as well start conservatively with 5000nS and reduce them if the machine appears to be slower than it used to be.
Just transfer those pin assignments to Stepconf, and it will probably all just work.