Elumatec SBZ 130/01 retrofit

Dear tommylight,
I sincerely apologize for taking your support for granted without doing my own due diligence, so I went back and read the entire thread from start to finish to enhance my understanding a bit better before asking anything else. Unfortunately, I am a student with little to no prior experience within this field (mesa, linuxcnc, machinery). While I understand everyone here is quite busy and their time is invaluable, I would wholeheartedly appreciate some guidance from experts like yourself. I also spent a lot of time reviewing the wiring diagram as well as physically cross-referencing things with the actual machine, which helped my insight quite a lot, however, I also have ended up with many many more questions.

1) I have confirmed how the ATC operates, it uses the same 4-switch grayscale sensor within the gearbox to check in position as well as indexing, however, the actual motion requires the spindle to be 'straight' so that the tool ends can slide into a locking area, at first I expected this to be done by the absolute encoder, since there's no sensors or anything for reference gtgrips in the spindle system, however after checking the wiring and the DARC manuals, they are listed as 'resolver' cables, specifically 2 pole resolvers which as far as I have seen, cannot perform this function, please let me know if otherwise.

2) the same is true for ALL the axis motors, except the long X axis, (no short X axis in this machine, 2001/2003 model sbz 130/01, but everything else looks the same as yours ), but only the X axis I have found some sort of spring based limit switch that can be seen for referencing trips, but I have also reason to believe these might just be for emergency and is it possible these resolvers can be used as absolute encoder functions (no homing).

3) after some research into Linuxcnc and mesa cards configuration, I have understood the choice of your mesa cards (input cards, output, analog control for the servos, FGPA card, connector, etc) however I would like to know how compatible your set of files/card combination would be in this case for me.

Once again I am deeply sorry for my earlier ignorance, it is simply my lack of experience, and I would really appreciate some guidance in these questions as well as my future doubts, and I will do my best to be vigilant in my own education on the matter. 

Thanks for the advice, Tommy.
After reviewing all the information exchanged so far, do you think it's a good idea to start a new thread about retrofitting our Sbz 130 model?
Basic differences include:
1) all 4 motors are AC 3 Phase, with integrated 2-pole resolvers
2)no short X-axis
3) newer DARC system (drives motors) (manual attached)
4) possibly different mesa configuration (6i24 7i49 for resolves feedback and - 10V of analog control signals for motors?)
5) 2001 model
6) No pneumatic brakes are used for the x and y axis but we did notice some sort of pneumatic counterweight or brake for the z-axis (picture included)
7) In the picture you can see the 'DARC system' comprises of from right to left: supply module, that receives AC 380-415 3ph, then distributes through dc links (metal bars under the grey boxes)  L+ L- PE to the other drives (spindle, x, y,z), diagram attached as well.

Attached is a picture I got online of the control panel with all the connections intact of the same machine 2001 model. The next picture shows the internal connection on the top side of the spindle motor. The next picture shows the cables for the resolvers found in the DARC manual. A picture of the whole machine in its current condition is also attached. A table containing info about the motors used is also attached. A diagram of the DC linkage is also attached that distributes power to all drives sharing and originating from the supply module, all drives also have inbuilt inverters to send 3 ph AC to their respective motors.
This is a link containing the DARC manual and the electrical schematics for the SBZ 130 - we.tl/t-zhbMsN1qWM
 

Forgot to include the picture of the Z-axis so here you go. Also noticed that the y and z axis uses the ball screw mechanism while the x-axis uses rack and pinion mechanism.