1999 Bridgeport ez Trak conversion

I want to convert our 1998 Bridgeport EZTrak machine to LinuxCNC. i want to keep as much of the original hardware as possible.
keep servos and encoders both work with the 7i77
I plan on using mesa 7i77 and 5i25 or 6i25 and i want to use a dell OptiPlex 9020
I have the books and wiring diagram
I know i need to connect the motor drivers and ends stops to it
I dont know what else i need to connect to is
I whant to add a mpg (what is a good one)
the head is manual but i want be able to start it with the computer and make it so it can use the estop
I am very new to milling this machine is just not cutting it with how old it is (I got it for free)

how hard would it be to use the cnc part of the machine with out changing it using to old pc and how to do it

Yes I want to reuse the old pc until I use it some then switching like 6 months down the road how would I do that

The dell is not in the machine I plan on using the chip on board that is in the machine now and using a laptop with a usb to rs232 adapter and doing something for now so I can use it for a wile and then put in a Mesa card like 6 months done the line

If the machine is running now, keep using it till it quits.
Bridgeports conversational is pretty hard to beat for 2 axis machining.
I believe the company is called EMI that specializes in reparing EZ controls
It is pricy to keep them running though.
whats inside that cabinet wont run LinuxCNC
drives and motors are usuable though
Ive owned a couple EZtraks and a Ezpath lathe
Im not talking you out of retrofitting, just that a usb-232 converter would
only let you load programs.