The model 12 flame spreader is the same one used in the model-B burner found on most glass lamps.
There are two styles of model-12 fonts. The black one on the left is known as a "slant" side, and you can see how the sides of the font slant inward from top to bottom. The Nickel plated font on the right is a "straight" side font.
Model-12 fonts were sold in different finishes. The most common were brass, or nickel plated brass, but as you can see in the photo above they were not the only finishes available.
This is an original 601F shade. It is one of the most sought after 601 style shades.
This is an original 601S shade also known as the log cabin shade. It is a very popular shade with collectors. Part of the scene is painted on the outside of the glass while the rest is painted on the inside.
The 601 shade has been reproduced in many scenes and colors. The reproductions are known as 601R shades. The original 601 shades have a "drape" design at the top of each panel where the arrow is in this picture. The reproduction scenic shades will have a clear skirt like the original but they will not have the drape design at the top of each panel.
This is a 601R shade and if you look at the top of the panels just below the rim there is no "drape" design. However the most obvious difference in painted shades is that the lower skirt on the reproduction is also painted while all the original shades have a clear skirt. (at least so far)
