This is regarding the plea about the Ampico B spool motor being weak.
Been there, done that.

When I first got my B I had two problems with my motor:  (1) It sounded
kind of "buzzy", with the buzz being speed dependent.  (2)  Weakness.

The first problem arose because the black goo that is used to embed
the commutator strips had oozed out between the strips, making little
ridges.  The buzzing was the sound of the brushes rasping over the
ridges.  Apparently the motor had sat in one position for many years,
perhaps in a very hot environment.  In any case, the "ooze" was limited
to one side, suggesting that gravity had something to do with it.

Solution:  Very gentle turning on my lathe with a very sharp tool
restored the roundness to the commutator.

The weakness originated from one source, but it caused a double whammy.
The bottom line is that while the motors are very high quality, the brush
holders are made of pot metal.  This swells with age, which causes the
brushes to stick.  Bad contact will weaken the motor torque.  This also
leads to arcing on the commutator, which in turn leads to arcing at the
regulator points.  Even if you clean the regulator points, you only get
temporary relief.

Solution:  There is a machinist who sells B motor brush holders made of
brass.  I am having a 'Senior Moment' (I forgot his name), but Craig
Brougher has the contact info.  I found the replacements to be of very
high quality, and installation solved the problem.  Be sure to clean the
regulator points as well, with very fine (#600) sandpaper.

The other thing you might check is the resistor values in your power
chain.  There are two resistors, one in series with the line.  It is
adjustable according to your line voltage.  The other is across the
points, I vaguely recall something like 340 ohms.  Chances are these
resistors have drifted up in value, which is typical of power resistors
of that age.  The proper values are given in the B maintenance manual.

A. B. Bonds