Well let's start with the things that we know for certain. Victoria became queen in June of 1837. My guess would be that it would have been at least a few months before razors with her stamps would have gone on to market so probably the earliest it could be is late 1837 - early 1838. We also know that her reign ended upon her death in January of 1901. Of course the late dating is superseded By the existence of the McKinley tariff which had effect on stampings in 1891. So it absolutely has to be between late 1837 to early 1891 but by the look of it my guess would be somewhere in the 1840s to 1850s. I don't have a definitive answer on when the regal stampings ceased but I'm sure someone will chime in.