Three phase 50 V. Help wanted

Hi, Gents.

I stumbled across and joined this Group yesterday, and would
participate with your indulgence.
I am endeavouring to patch together an odd "homebake" assortment of
gear of various vintage to build a multiple axis CNC controller.
The history of the project goes back some years to a time when large-
torque stepper motors, power supplies and controllers were
prohibitively expensive or unavailable.
I decided to cheat.
The system I originally envisaged would use a vector type graph
plotter, the motors of which (minimal in*oz torque reqired) are to
drive the mechanical inputs of some lovely little WWII vintage torque
amplifiers which I have, which talk Ft*lbs at the output and could
win arguments with young stilson wrenches. These outputs are to drive
the 1" diameter ball-screws I have for my X-Y-Z table project, or
axis wheels on mills, or whatnot.
My problem is that the torque amplifiers have 50V 3-phase motors
(50Hz, 1/40 hp, 2750 r.p.m.) which are integral to the units.
Repowering them with single phase or D.C. motors would be a mission
and I am attempting to build a 3 phase 50V power supply to run from
single phase domestic supply (230V, 50Hz, neutral-earthed).
I have built a "Rotary Converter" prototype from internet search
info,....which doesn't work....
Can anyone help me with it, please ? Any suggestions for a good CNC
controller ?
I will not take up space here with it again, but can supply details
to anyone kind enough to respond.
Alternatively, someone might want to convince me that I am on a
Fool's mission and steer me toward some particular controller / power
supply / stepper-motor configuration that would be appropriate. I do
not have any Brand-familiarity with CNC gear at present, but am
learning here!
Incidently, the Torque Amplifiers are from 1941 mechanical
analogue "Predictor" units used to coincide artilliery shells with
bombers and set the time-fuses to the time-of-flight. Amplifiers were
used to boost the output of a mechanicat integrator(!) of Euclidean
elegance which involved a disc driving a cylinder via a sphere with
pathetic work capability! Cylinder-angle = INT(Radius of ball
contact.disc-angle).
Now shells are smarter than guns, and everything has gone
digital ......sigh....

Cheers, Gents. Don.