yours has the 481 controller the same as mine.
it would be extremely hard to convert to mach etc!
if its working use it as it is.
i have a program to write gcode to floppys on a pc which will read direct in 481 controller.
i also have working postprocessors for alphacam and bobcad. see my other posts for details and what it can do.
if you do decide to upgrade il buy your old controller from you as a spare!