Vanguard 3000 engraver retrofit

Hi, I was going to build a CNC router from surplus parts as a learning
project for the CNC hobby but I've inherited a fully functional Vanguard
3000 engraver manufactured by New Hermes in around 89, the controller
and software are pretty archaic so I want to retrofit it to use a modern
PC with either windows software or EMC, it has Sanyo Denki motors.
Anyone have schematics on this guy? I've already emailed new hermes for
a manual but I dont expect a response until after the holidays so Ill
start ohming it out and drawing my own until (or if) I can find a
manual.
The power supply is a separate card in the controller box so I am hoping
I can just build a new enclosure for it to keep from buying a power
supply.
If I can use the existing power supply I am thinking all I will need is
some motor controllers, the software and the knowledge of breaking out
the parallel port which I've found on the web already. Am I on the right
path here?
Any recommendations on software or any pitfalls I might encounter? Seems
like a good project to learn the basics of motor wiring and control. My
planned path of progression is to do this first, then build my router to
tie in the mechanical movement design knowledge, then a plasma gantry.
Thanks in advance for any help you guys can provide.
Darrell