Newb retrofit question

Hello, 
     I have acquired an older (mid 90's) industrial cnc plasma table. I got everything working and had the control doing whatever preset shapes were installed on the old DNC 2.8 controller before it was taken apart and moved. What I want to do is retrofit a different control to this machine using as much of the existing parts as possible. I'm new to cnc other than what i've read on 3d printers and whatever info I've picked up fooling with this plasma. 
So far I'm thinking of going with Linux CNC as the controller.
I *think I need some kind of control card to talk to the servos. mesa? (do I need just 1 or one for each servo?) 
I'm not positive I need a power supply yet. I believe I can take the one out of the old DNC control box and reuse it. Suggestions? 

I have no idea about height control yet. I don't believe this has height control so I may want to integrate that. 

I want to be able to program custom shapes for cutting. Pretty much what most of the newer plasma cutters seem to do. So I'm open to suggestions on which direction to go. 





 

Linuxcnc would be a good solution to retain as much as you can but as Tommy said the drive type is what is required. If they are analog +-10v controlled, the Mesa 7i77 plus maybe some additional cards for extra IO. Or the newer 7i97 ethernet card. But lets visit that later when the drives are understood.

The Mesa THCAD card allows you to read the torch voltage. This  lets Linuxcnc perform the THC function for you so there is no need for an external THC
If you don't have a Z axis motor or torch lifter, you may need to add a servo or stepper motor to the torch lifter.

The linuxcnc QTplasmac config, does have some basic conversational shape capability.

I'll see if I can find anything on the voltage. The book disappeared a while back, but from what I remember it mostly had info about how to manual program G code in it. No schematics really.
The servo motors look to be CMC model: MT2630 if that helps anything. I'll take a look at the stuff a little closer tomorrow when I get some time.

Alright I finally got time to look at the box of parts I have more. Doesn't look like there are any books.
The pictures I'm attaching are of the encoder I guess it is (it says something about signal voltage). Along with the gear reducer and model of the servo.
Is there anywhere else to look for the information? I did search online for more information on the servo but didn't see whether or not it was the +-10volts.

 

Nothing separate as far as drives unless I take apart the DNC control box. Everything was wired to that. Attached is a better picture of the back of the box.
The aluminum pieces with the fins on the left were labeled x axis (or maybe cross axis) and y-axis.
 

I think it would be worth removing the top cover to see whats inside.
The heat sinks are made by the motor manufacturer. One of them is labelled power so it will be interesting to see whats on the other side of the heatsinks as I would expect the motor manufacturer has supplied discrete drives. If there was a model number you may be able to find documentation.

Bringing this back as I've finally dug this out of the corner and taken yalls suggestion of taking this apart. 

Looks like the model number for the axis control boards are D41-17445C
and the power supply board is D41-17337B

I've been searching for any wiring diagrams related to these things but haven't really turned up much. One of those free pfd places let me actually preview a CMC maintenance manual which looks like it has a wiring diagram for the control box but was too blurry to read when I zoomed in. 

The driver board does have a place for a tach as well. 

The servos only have 4 wires going to them, I assume plus and minus for power and two tach wires based on that I can read on the control board.
Part of the driver board has wires going directly to the power supply, the rest goto the main control board of which I can't really figure out what they are supposed to be doing. 

Would it simplify things to simply get a driver that can handle those servers? 

Do you have the part number of the drives?
Can you get a picture of the drive connections

(The drives are the modules with the aluminum heat sinks)