@ Byrdie

Looks like it says M kitty or Kay or something like that. I have done many where out the 4 previews 1 will have a sig of some kind. I know Da Vinci's sig especially on mechanical and schematic type drawings drawings are very distinctive and the images I've done done in Da Vinci style that have a sig  have that distinctive design or close to it but it's not his sig something else don't know what it is I think it's just in keeping with his style art. I don't have any problem using the images however I just do Art for fun never commercially if you're making money off it that's another thing.

Remember...No matter where you go there you are