Mystery Item thread.... What am i?

[Darkwood]

This is out of an old Russian lathe it has 4 contacts on it 2 x NC and 2 x NO it has a coil and on top it has a sealed oil filled reservoir.
What is its function!

Spoiler alert!!! Answer in post 9!!!

 

[Des 56]

Nice work DW. Ideal for 10hp or thereabouts. If you decide to upgrade your sofa with an automatic starter we run a scheme here at the museum to convert redundant switchgear into beer. We do not presently have any manual star-delta starters at all, when I tried to salvage one from a capstan winch not long ago it got lost on site.
I.e. don't chuck it out.

About 15 years ago,which still seems like yesterday,I was stripping these out of an old NCB works by the bucket load
I made quite a few up with the best bits out of multiple units, they were still being used in the then factory units until the place was redeveloped
Its like many things,I could have saved as many as you could have wished for,but its not till years later that their historical value is appreciated ( I wonder if the modern spark would even know about having to swing that handle, and at the right time)

Likewise,when the coal tip near me closed,there was switchgear from years before I worked at the mine,that had to be 30s or 40s gear
Reyrolle switches that as kids we called the Robots,they were just scrapped,what a shame that is now