Remember the "Collector Edition" for their version of "Beyond the Mountains of Madness" adventure? The one that came with a crate and all sort of stuff?
https://www.youtube.com/watch?v=myPHIXIEs7QIt seems that they did the same with their "Au coeur des années 20" supplement about... the 1920s. It was done late in the 6E era, but it is still available on eBay France for 300 Euro. It comes with:
- A champagne case, in solid pine with a sliding cover, fire-marked
- A hardbound book of 528 pages
- Stainless steel "bootlegger" flask, 270 ml, engraved with the symbol of the ancients
- A pair of cufflinks and tie clip, engraved with the symbol of the ancients, and their box
- The "Bathing Beauties" calendar of the decade (1920 to 1929), in A5 format, spiral binding
- 8 postcards "memories of the decade"
- 2 posters format 60x40: a political planisphere and a planisphere of the communication routes in 1929
- A US $ 20 bill from 1929, serving as a numbered certificate
How comes that Chaosium was never interested/capable to do these kinds of marvels is beyond me.
Edit: I put this one here because it has no RPG contents at all, not even for CoC. It only wants to be the definitive guide to the decade.