I have a Cookson Lockstitcher no.744 complete with case, is it of any value?

I tried to look for an answer for you. But, I came up with nothing. Sorry! I know that my posting a response to your question will get your question moved more to the top of the list of questions to be answered because I have done this. Maybe someone will have an answer for you.

To the right collector,

Here is a web site of a company that will give you a formal apprisial.

SEWING MACHINE VALUATIONS BY SUSSEX SEWING MACHINES

They are English machines, first patents around 1887. The condition will make a big difference in values

They are considered very rare, most found are in very bad shape,