That spike is a wedge, when hammered futher in (from the wider end) the sides force expansion. Looking at the photos, but not being able to see behind the cover I can't see the purpose of the wedges. The Brass ball at the bottom of the beam is an oil holder, which dripfeeds, or in some cases feeds by a wick, oil to the pin and bush below it.

It's not paint or metal. If you have a look a few photos on, the connecting rods are wood, and the stain colours make for the contrasts. It just goes to show the skill of the craftsmen that made these machines

What amazes me is the attention to detail and perfection in things like the countersinking depth for the name plate srews, The nameplate itself, just for a wheel. The finishing of the thread end of the shaft. The engineers that made this equipment, considering the technology of the time, were true craftsmen. Very rare to find now days.

This kind of equipment was common in that period for ECT treatment, or Elctro Convulsive Theropy ( http://en.wikipedia.or...roconvulsive_therapy ). In the early days it was used rather alot and for nearly everything, seen as the wonder cure in the psych field. The missing instrament , may have been a volt meter, but more likely it was an occiliscope.

It's the remains of a ventriliqusts doll, used in theropy with kids