It means, not working steady on it. I had forgotten it, found it again, and then finished it. I have folders of images in different stages of work. If I am stuck, then I work on another one. Sometimes I loose a folder!!
No Burton the artist. Tom or Tim. He draws trees like that and I believe he does kids stuff.If I can find more info I'll tell you. But you are right about Richard Burton, He was married to Elizabeth Taylor.