Yea, those symbols don't seem to be included. I am guessing that the image was an early working draft from the artist, and that those particular items never made it into actual symbols. The actual annual isn't usually done by the time they advertise it.

Knowing that people have different things going on in their lives, and while a week technically should be enough if one can dedicate all your time that week, most people won't be able to do that. My suggestion is just do a month, run the entire month of May for example. This means you can take a few days and think up a proper announcement post. Take the feedback gained here (perhaps more will come) and then write up a new topic, declaring the challenge and explain the rules (hint: try to be focued, but not overly strict. A common theme to give people ideas and compete in the same space is fine, but too strict rules scares people of (ref the usage discussion above)).

I can then give that topic a temporary sticky status for the duration of the challenge.

If anyone wants to arrange such a challenge, feel free to do so. While I don't have the skills required, I'd love to see a competition going on for those that have, and maybe there will be some nice results for everyone to use.

But I think Shessar is right. If you force a specific style, you will be excluding lots of otherwise skilled people. While the symbols produced will be less usable overall because they don't have a single style, it wil allow everyone involved to do their best instead of being forced to try to emulate some one else's style.

My suggestion would be to introduce a theme though, such as "dungeon treasure" or "modern supermarket" or "overland trees" to both give people ideas and constrain it somewhat without being to limiting.

And I don't think splitting it into vector and raster symbols is a good idea. You're already cutting deep into the possible participants when you go from maps to symbols, so splitting even more isn't wise IMHO.

I was looking at this for processing, but I noticed you've used a nonstandard compass rose. I need you to replace this with an atlas appropriate one.

The installer should find the data directory automatically during installation. Are you installing the correct version (i.e. the CC3+ version and not the older CC3 one, from your description it sounds like you may be trying to unzip the CC3+ compatible support files for the old tome instead of installing the proper full CC3+ version).