He did do it all himself I believe. There was suposed to be a mini coming out written by Brian Azzrello (I think) and each issue would be drawn/painted by a different artist. Lee and Del' Otto are the only ones I remember attached to it. But then All Star and Wildcats came along, and are now way behind, so that may have been canceled. I was really looking forward to it.
(Batman: Europa, if you wanna look it up.)