The sight glass on the side of the Stanley had been replaced at some time in its life and wasn't made correctly. It was a glass tube with a 5/8" OD cut just long enough to pass thru the brass rest and glued together with RTV.
After reviewing original pictures I learned that the tube is supposed to travel passed the rest and right into a clearance hole that was drilled into the structure supporting the seat. The purpose of having the glass this high is that when the Stanley has a full tank of water and is parked on an angle the water won't start pouring out of the top of glass.
The new glass is actually 3/4" OD acrylic tube. I had to turn one end down about 15 thou to make it fit snugly in the lower casting. Acrylic is a great product to work with, cuts like butter.
Old sight glass. Note the RTV and wooden shim.
