Sattley was a line of engines, (and possibly other products) sold by Montgomery Wards. Some of the engines had a hopper on top for water to cool it, and two large heavy flywheels, some were air cooled and looked much like a modern lawn mower engine.
I am not the most knowledgeable member here and do not know what a "Royal Blue No. 35" is,
but some one here might.
If you could post a picture, that might help.