I have a Watco floor jack I bought new from the auto parts company I worked for.
It's rated 1 1/2 tons and is the size of most 5 ton jacks. I think I paid a $100.00 or so, at cost.1962
I like it because it's so long and has a high lift and a T handle to move cars around the shop.
I need to reseal it. Served me well.
I have had several hydraulic bumper jacks that I've sold.
I just never saw a " Scott-Atwater " jack of any kind.Learn something every day.
I had mechanical bumper jacks that were simaler in design.
Thanks for sharing your photos.
Roy