You can't order this through Diamond anymore. But Dave's Sim trawl through his pre-Cerebus career will illustrations, documents and letters to and from the great and the good is a very personal journey. And no mention at all of anything relating to Cerebus #186 yet, that was far far far far in the future.
If you want a copy, see if your retailer is ordering direct from the publisher. Or you can find individual issues here.