Original Art Stories: The Ghosts Of Avengers Annual #10 , Part II
As for ghosting and or assisting among professionals, lots of ink artists do it and I was not an exception. I assisted/ ghosted for the following over the years w/o credit: Vince Russell (Cable over Ian Churchill and Thunderbolts#1! over Mark Bagley), Mike Oeming (Ninjak over Neil Vokes), Norman Lee (Magic: The Gathering over Pop Mhan), and a lot for Mark McKenna during the dry mid-90's (Magnus, Robot Fighter, Tangent's Metal Men, JLA: World Without Grown-ups, and Vext, all over Mike McKone, Teen Titans over Phil Jimenez, Nightwing over Don Kramer, Magnus over Hannibal King, and Aquaman over Jim Calafiore. And I had some established inkers ghost or assist me occasionally w/o credit such as Mark McKenna (over Sal on Black Panther), Jim Amash (over Leonard Kirk on Ultragirl), Phyllis Novin (over Sal on Black Panther), Warren Martineck (more stuff than I can list but lots of BP was among them), Steve Montano and Aaron McClellan (both over Sal on Bloodshot), Keith Williams (over Steven Butler on Ultraforce), Jeff Albrecht (over Mshido on Batman Chronicles), and Sal Velluto (over himself on assorted pages).
This info is usually kept on the downlow but trust me, everyone does it at one point to help someone or help for themselves.