Bill: Were you able to find and read the serial number and engine number?
I have found that shining a light, like a focused-beam flashlight across the surface where the numbers are stamped, will often show a shadow of the stamped number, where shining a light directly at the number washes out any contrast in the stamped metal surface.
Also, sometimes taking chalk and rubbing over the stamped surface then wiping the surface off. This sometimes leaves enough chalk in the stamped number depressions to be able to read the number.
I have a few engines that are very, very hard to read.. even with a magnifying glass and using various methods of lighting and coloring the stamped area. Sometimes the stamping was so shallow that even surface rust will level the surface and obliterate the numbers.
Best of luck.