That's supposed to be left ankle.
My A/C compressor also just quit; the fan works fine.

It is always in the low pressure line.

Don't have them, even if you had them ,it sounds like it needs a recharge .
Seems like most cars around then used R12 , kinda hard to get a hold of.
Check into doing a conversion to R32 maybe ?

You must have a proper refrigeration gauge set to correctly
service any AC unit.

Look on the face of the blue gauge. You'll see there are
scales on it besides the pressure. Those scales are noted
for type of refrigerant and show you the normal temperature
for a particular gas at a particular temperature.

Let's say it is 80 degrees outdoors and you hook the hose
to the low pressure side of the system. The needle should
be pointing at 80 degrees on the scale marked R12. If it
isn't, and reads lower as is the usual case, then you don't
have a single droplet of Freon left in the system. This is
done without the engine running or the compressor engaged,
of course.

Once you have the system running and well charged, the
correct pressure is the one that corresponds approximately
to 30 degrees on that scale while the compressor is running.
At that pressure/temperature no ice will accumulate on the
coil inside the vehicle.

Also look around and find the sight glass that most R12
systems had on them. You can watch that while charging
and the correct pressure/temperature should be achieved
at about the same time as all bubbling in the sight glass
disappears.

There are no "normal pressures" for the high and low
sides in the context of some single small range of
pressures being correct because refrigerant systems
are saturated and pressures are temperature dependent
when not operating.