The bulbs that were in the clock are marked 7.5 watts. The reason I went with the cfl's is the whiteness (the clock face has some discoloration that shows under regular light), and the heat factor.
Do I know the age of the range?
I can only guess on that. I have two owners manuals. One was printed in 1936, the other, 1940. The 1940 edition most closely matches my range but is probably older. I would say this would have been the range being produced right up until WWII stopped civilian production. Or, it may be what the company turned out immediatly after the war. Landers brought out the SpeedLiner series (very round and bubbly) in 1948. Mine is a Mercury series and was one generation up from when the ranges came with legs.
The Speedliner series was the last ranges offered before the company sold off the entire major appliance products in 1952.
Mine does have infinate heat control on the "burners" or should I say "eyes". I have yet to figure those out - I have not begun to tear into this stove. One interesting feature about the control knobs, is right behind the panel. A "cam" shaped "door" controls the amount of light source coming from behind the panel that ends up illuminating the red "jewel" above the control knob. Presumably to show the user how high the heat is selected. I am interested in seeing what this looks like in operation. As of yet no power has been applied to any part of the range. It needs to be worked on - a lot.