I have the same sketch that hector has plus another one done by the same artist. I also cannot read the signature. I've been trying to find the artist and I'm curious what it would be worth. Can anyone tell me?

Who is Hector?

If you could please upload an image of the painting with you,it will be easier for someone to recognise the signature.

The artist is russian born-his name is Arthur Boris Klein-aka O'Klein