That is a product with the Witherby name and likely nothing to do with the T H Witherby legacy, at least to my knowledge.
If it works well, be happy and use it.
It may be someone who had rights to use the name. It may be the trade mark to the name has become public domain.
There is also Witherby Publishing, seems to be mostly maritime titles.
It also looks like the kind of product many hardware stores would carry to sell to women looking for a stocking stuffer for their husbands.
More research would be in order if it is something you have to know.
jtk