I have a domestic sewing machine . The numbers on the needle bar is 1858 40 . This is a treadle sewing machine. I am not interested in selling it but would like to know the year it was made. If anyone could help that would be great!! Thank-you in advance.

I was not able to find a date. It doesn't mean that it isn't out there on the Internet somewhere, though.

There is some interesting information on the Domestic Sewing Machine here: The Domestic Sewing Machine Company

It might help you to contact people on that site.