Sorry for the late reply... life intrudes. The only markings are the patents on the back of the head.
I'm not sure, but I thought they were made from the 40's thru the mid 70's. Don't know how you tell specifically. HERM
I don't believe the exact year of manufacture can be determined. The Stahly Live Blade razor was made during 1946-1978 in South Bend, Indiana.
I've also looked for dates on these razors but have never found any info. Only thing I ever found was this thread on another site about different models and cases......... Several models were marketed from 1946 until the 1970s, differing mostly in case and finish. Later models of the razor were available in a presentation case. A clear plastic upright box case was also available by 1947. A wood-type upright case in early (1946) advertisements. Original models were chrome, gold plate, or black with gold plated accents. Later models were also available in a brown bullet-shaped leatherette presentation case. Late models were also made from aluminum. There were women's models that are pink and chrome (the pink is a special surface painted on the handle).
