So I finally purchased a copy of the Cerebus Cover Treasury. I'd provided IDW with two scans of cover prelim's I own, for #11 and #36, back when the book was in the planning stages, but I'd never heard whether the images would actually see print.
And now my wait is over: neither were used.
But it occurs to me that other AMOC regulars would like to especially see the #11 cover -- a hand-coloured example not unlike the #15 shown in the book. Dave doesn't mention it in his commentary but I seem to remember the #11 original art being sold on eBay and then he did the #11 re-creation shown and auctioned that on eBay not too long after... which didn't sell for nearly as much as the original.
(I paid much less than either the original or the recreation for the hand-coloured example.)
It was nice to have Dave's corrections (or whatever he called them) to the book posted on AMOC, and hopefully for other fans the #11 cover is a similar nice addition.