In response to Lynn Bullock's question about the odd spill units,
I am sure that they have nothing to do with the description in the 1929
Ampico manual.  I assume that they are placed there to bleed the stack
so that on rewind the notes nearest to the rewind slot will not sound.

The units would most likely be tubed to the rewind port on the
transmission frame, or somewhere down the line from it.

Bruce Clark