Nelson-Wiggen made the style 8 coin piano with at least five types of
instrumentation.  Each style was sold either with art glass or plain
glass with a decal in the middle and a curtain:

1. Reiterating xylophone and reiterating bells.
2. Reiterating xylophone and single-stroke bells.
3. Reiterating xylophone, A rolls.
4. Single-stroke xylophone, 4X rolls.
5. No extra instrument, A rolls.

Variety 1 is the most common.  Every example I've seen plays A rolls,
and all or nearly all have art glass.

Variety 2 usually plays A rolls, but I think there's at least one
original example tubed to play 4X rolls.  I don't think the latter
ever plays xylo and bells at the same time, and I don't know how
the alternator mechanism works from the 4X lock and cancel holes.

Variety 3 always plays A rolls.  It has an A-roll tracker bar with
two elongated holes near the right end for mandolin and xylophone.

Variety 4 always plays 4X rolls.  It has a 4X tracker bar with only
one elongated hole near the right end for mandolin.  It always has
a lock and cancel valve for turning the xylophone on and off from the
appropriate tracker bar holes.

I've only seen one example of variety 5, at Svoboda's Nickelodeon
Tavern in Chicago Heights.  Dave Ramey Sr. added a set of single-stroke
bells to it.  Its whereabouts are unknown today.

For variety 1, there are at least three different "alternator"�
mechanisms for switching between xylo and bells each time the "A" roll
calls for an extra instrument.  The standard version has a little
flipper that is pushed back and forth by one of a pair of small
pneumatics each time the extra instrument turns off.

An improved version of this has an extra connection teed to the shutoff
because of the propensity to get stuck in between the two instrument
settings whenever a roll had a perforation missing from the "xylo on"�
chain perforation, a fairly common occurrence which would cause it to
not play either extra instrument until a person reset it.  The shutoff
connection forced the flipper all the way back to one side of its travel
so the extra instrument would always work, at least at the beginning of
the tune.

The third type of mechanism had metal hooks that mechanically pushed
the flipper back and forth, but it apparently wasn't as reliable as the
pneumatic versions.

Any of the five varieties could be ordered with either mandolin or
banjo attachment.  The banjo attachment had a slotted curtain like
a mandolin attachment, but each tab had a wedge-shaped wooden tab
instead of a metal clip.  The original patent for the banjo attachment
stated that the letoff was supposed to be adjusted so the hammers let
off normally when the attachment was off, but they would block the
wooden wedges against the strings when it was on, causing a very
staccato, metallic, banjo-like tone.  Unfortunately, few collectors have
ever been aware of the banjo attachment, so most examples that had one
have been converted into an ordinary curtain-style mandolin.

There were several other case designs for small Nelson-Wiggen
keyboardless pianos, including the Casino (or Casino-X when fitted with
a horizontally-mounted xylophone right under the top of the cabinet),
the Banj-O-Grand (which had the banjo attachment), and a very early
instrument with three ranks of reed organ reeds instead of a piano,
plus percussion, playing style G rolls (the 4X roll arranged for
single-stroke xylophone hadn't been introduced yet).

Since original N-W advertising only identified these instruments by
case design, I'm convinced that any style 8 N-W case should be called
a style 8.

Another variation that has been seen in examples of the style 8, 4X,
and 6 is the ABT target mechanism.  This was mounted in one of the
windows in a 4X or 6, or in a cabinet extension atop a style 8.  It
enabled the customer to try to win tunes by hitting targets.  The style
letters were 8T, 4T, and 6T, respectively.

The A.C. Raney Collection, which was eventually sold to Walt Disney,
Lyle Kellogg, and a third buyer, included a very small, odd N-W cabinet
piano that had a xylo under the lid like a Casino X but also had two
triangles with the beaters facing each other.  Does anyone know where
it is now?

Art Reblitz
Colorado Springs, Colorado
http://www.reblitzrestorations.com/