Ingersol Rand Crowe Safety Saw

I see someone requesting Information about one of these saws. My Grandfather bought one in New Zealand around 1920's. It is hanging in my Shed , It goes, Has a , 3 piston air motor, the blade turns opposite rotation to a regular circular saw it turns at a much slower Rpm than today's saws which would have been great to cut Australian Hardwood for bridges which was it's main job
I too have looked for ages for information and have drawn a blank till this article came up and would like to make contact