Mercury. Made in Edmonton, I was told. One of the double wheel grinder/polisher at the rock and gem club shop is Mercury. They were considered very good units. The grinder/polisher unit reminds me of the Frantom unit I redid. The Frantom is an interesting name, Tom was the owner and his wife was Fran.
The club's 10" is ( if memory serves me right) is an original Highland Park as is my wife's. They use a pulley, weight, and wire for feed. I wonder how that Mercury does the feed.
The club's 10" gets a lot of use and abuse. Members pay by the square inch and the 10" is is the least expensive. They member try to speed things up by pushing. Thin lapidary diamond blades get quickly warped.You can't push !!! Even thin construction blades die. This time I put a HD "turbo" construction blade on. It cuts for a diamond blade a wide kerf .
We use food grade mineral oil,. It's also used as laxative for cows. Dairy equipment suppliers are one source. It doesn't mist much. and is safe. The Langley club uses hydraulic oil , it's cheaper. From working with hydraulic oil, it can cause rashes and stuff. It's the additives.