(Part 2) Top products from r/callofcthulhu

First of all, that's amazing. Great idea for a dice box or dice rolling tray.

Have you considered something like a holder for minis, dice, pens/pencils? Basically little compartments inside for a player kit. I've seen a websites selling custom wooden enclosures for dice, pens, and minis for D&D players but a copy of the Necronomicon for a CoC game would be amazing.

Book ideas:

• There are a lot of collections of HP Lovecraft tales, many of which have great covers. I would particularly look for ones that have especially popular titles on their covers. "Call of Cthulhu and other tales" looks more fun than "Tales of HP Lovecraft." Of course, cool looking covers trumps all. https://www.amazon.com/Complete-Cthulhu-Leatherbound-Classics-Collection/dp/1435162552/
  
• King in Yellow (as SamEire93 said)
  
• Necronomicon (as you said)
  
• Der Hexenhammer - an actual book often referenced in CoC and with a really cool name.
  
• Malleus maleficarum - A translation of the Der Hexenhammer which still has a cool name.
  
• The Lesser Key of Solomon - A real book sometimes used in CoC games and which has a cool cover. https://smile.amazon.com/Lesser-Key-Solomon-Aleister-Crowley/dp/0998136417
  
• Book of the Dead (Egyptian version) - An actual book often referenced in CoC and with a really cool name.
  
• The Book of Eibon - I'm not sure there are any decent looking copies that exist, but the concept is good.
  
• Penny Dreadfuls: Sensational Tales of Terror - has a cool looking cover: https://www.amazon.com/Penny-Dreadfuls-Sensational-Leatherbound-Collection/dp/1435162765/
  
• Lovecraft Country - Maybe? It's a great book so I'd feel a little weird having it hollowed out, but a fan might really like the idea.

It might be worth the effort to track down the old Star Frontiers adventure 2010 (based on the movie of the same name). IIRC, it has the deckplans of the Discovery and the Leonov. In fact, you might be able to harvest quite a bit from that adventure. The monolith can be either a Yithian or Mi-Go artifact.

Also, if it hasn't been mention at yog-sothoth, check out the adventure Bad Moon Rising for dealing with the Yithians and being in space.

If you have some time to prepare read the book the "The Longest Cave" by Roger W. Brucker & Professor Richard A. Watson Ph.D. It's a true story about cave exploration. It will really give you an idea for the sheer isolation of caving far underground.

When you go through a tunnel in cave you always have to look behind you when you exit a tunnel. Imagine later backtracking and finding two exits. Did you come via the left or the right?

You come to pool. The only way forward is too dive into the pool which you assume a U shaped tunnel. (Or is it a J?) Once you come up on the other side it is pitch black. Is your torch wet? Your matches soaked?

I recently bought a hardcover 5th edition from an Amazon seller for about $35. I remember a few listings of 5th edition for close to that price and some a little less.

Here's a few: http://www.amazon.com/gp/aw/d/0933635869/ref=mp_s_a_1_1?qid=1452440904&sr=8-1&pi=SY200_QL40&keywords=Call+of+cthulhu+5th&dpPl=1&dpID=61BczfT5a0L&ref=plSrch

I ignore prices at brick and mortar stores, but ~$300 is the starting price at Amazon marketplace (https://www.amazon.com/gp/offer-listing/1568821565).

http://smile.amazon.com/Call-Cthulhu-Horror-Roleplaying-Lovecraft/dp/1568821816/ref=sr_1_2?ie=UTF8&qid=1452378050&sr=8-2&keywords=call+of+cthulhu+rpg

https://www.amazon.com/gp/aw/d/1568821808/

There is also one for San Fransisco, Morocco, and other cities. You could also look at Gaslight which focuses on late 1800s London (at least I think it is London, I haven't actually read it).

The King in Yellow https://www.amazon.com/dp/1411685768/ref=cm_sw_r_cp_api_i_LWFBDb9HJGJ8K

See also http://simonbjones.blogspot.com/2015/04/what-is-notable-about-my-version-of.html

https://www.amazon.com/Petersens-Field-Guide-Cthulhu-Monsters/dp/0933635486

Yes.

The Haunted Realm by Simon Marsden is also a good one. All of the black and white photos were taken using infra-red film, which adds a layer of oddness and atmosphere to the images.